Catheter system for introducing an expandable stent into the body of a patient

ABSTRACT

This disclosure relates to a catheter system for introducing a heart valve stent into the body of a patient. The catheter system includes a catheter tip having a seat portion for accommodating the stent in its collapsed state and a stent holder for releasably fixing the stent, wherein the seat portion is constituted by a first sleeve and a second sleeve, said sleeves being moveable relative to each other and relative to the stent holder, and a catheter shaft for connecting the catheter tip to a handle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/407,560, filed on Jan. 17, 2017, which is a continuation of U.S.application Ser. No. 13/698,910, filed on Mar. 18, 2013, now U.S. Pat.No. 9,597,182, each of which is incorporated by reference herein in itsentirety, U.S. application Ser. No. 13/698,910 being the U.S. nationalphase entry of International Application No. PCT/EP2011/002524, filed onMay 20, 2011, which is a continuation-in-part of U.S. application Ser.No. 12/801,090, filed on May 20, 2010, and which claims priority toEuropean Application No. 10163478.0 filed on May 20, 2010.

The present disclosure concerns a catheter system for introducing anexpandable heart valve stent into the body of a patient. The disclosurefurther concerns an insertion system comprising a catheter system and ahandle for inserting an expandable heart valve stent into the body of apatient, as well as a medical device for treatment of a heart valvedefect, in particular a heart valve failure or a heart valve stenosis ina patient, wherein the medical device has an insertion system and anexpandable heart valve stent accommodated in the catheter tip of theinsertion system.

In medical technology, there has been an endeavour over a long period toclose a heart valve defect, such as an aortic valve insufficiency or anaortic valve stenosis, non-surgically by means of a transarterialinterventional access by catheter, thus technically without anoperation. Various insertion systems and stent systems have beenproposed, with different advantages and disadvantages, which in part canbe introduced into the body of a patient transarterially by means of acatheter insertion system, though a specific system has not prevailed upto the present.

The term used here “heart valve stenosis and/or heart valveinsufficiency” shall generally be understood here as a congenital oracquired functional disorder of one or several heart valves. A valvedefect of this type can affect each of the four heart valves, wherebythe valves in the left ventricle (aortic and mitral valve) are certainlymore frequently affected than those of the right heart (pulmonary andtricuspid valve). The functional disorder can result in narrowing(stenosis) or inability to close (insufficiency) or a combination of thetwo (combined cardiac defect).

With all known interventional systems for implantation of heart valveprosthesis, an expandable stent system is moved transarterially to aninsufficient heart valve. A stent system of this type consists, forexample, of a self-expanding or balloon-expanding anchoring support(also termed “heart valve stent” or “stent” in the following), to whichthe actual heart valve prosthesis is fastened, preferably at the distalretaining region of the anchoring support.

In the medical devices previously known from the state-of-the-art,however, it has become apparent that the implantation procedure of astent system to which the heart valve prosthesis is attached isrelatively complicated, difficult and expensive. Apart from thecomplicated implantation of the heart valve prosthesis as a replacementfor an insufficient native heart valve, there is the fundamental risk ofincorrect positioning of the stent or heart valve prosthesis with themedical devices used up to the present, which cannot be correctedwithout more extensive operative intervention.

The problem addressed by the present disclosure is the fact that medicaltechnology does not currently offer any insertion system in particularfor transarterial or transfemoral implantation of a self- orballoon-expandable heart valve stent with a heart valve prosthesisattached to it in which, on the one hand, the insertion system enables aminimally invasive implantation of the heart valve prosthesis in apredictable manner and, on the other, dispensing with the need to use aheart-lung machine during the operation on the anaesthetized patient.Consequently the operative intervention can be designed to be especiallycost-effective and, in particular, to reduce the physical and mentalstress on the patient. In particular, there is a lack of a medicaldevice for implantation of heart valve prostheses that can also be usedfor patients on whom, due to their age, an operation cannot be carriedout without the aid of a heart-lung machine.

Because of the increasing number of patients requiring treatment, thereis also a growing need for an insertion system with which a minimallyinvasive intervention can be made on a patient for treatment of a heartvalve stenosis and/or heart valve insufficiency in a preciselypredictable way, whereby the success of the operation is in particularno longer significantly dependent on the skill and experience of theheart surgeon or radiologist carrying out the treatment.

This situation also applies to operations in which heart valveprostheses with stent systems are implanted with the aid of a so-calledballoon catheter system.

It is also regarded as problematic that, when using systems alreadyknown from the state-of-the-art by means of which a heart valveprosthesis can be implanted in the body of the patient with minimalinvasiveness, incorrect positioning of the heart valve prosthesis or theassociated heart valve stent can frequently only be avoided when theheart surgeon or radiologist is especially experienced. It is indeedknown, for example, to insert a heart valve stent with a heart valveprosthesis attached to it into the body of a patient as far as the heartvia the aorta, whereby self-expansion or balloon-expansion of the heartvalve stent is initiated by external manipulation when the implantationlocation is reached, which should lead to a secure anchorage and precisepositioning of the heart valve prosthesis; such heart valve stentscannot usually be removed in a simple way, however, and their positioncannot usually be corrected once the stent has expanded.

Accordingly, there is basically a risk with the known systems that if,for example, the self-expansion or balloon-expansion of the heart valvestent with the attached heart valve prosthesis is initiated in anon-optimum position, due to a slip by the doctor carrying out thetreatment or other technical circumstances such as stent foreshortening,this position can only be corrected appropriately by means of a major,in particular operative, intervention, which must frequently be carriedout on the open heart.

For example, a heart valve stent for heart valve prosthesis is describedin document WO 2004/019825 A1. With this heart valve stent, distal-endsupport arches or hoops and positioning arches or hoops are provided,which can be inserted into the pockets of the native heart valve of apatient so that the heart valve stent can be positioned by means of thesupport hoops. Additional so-called commissural hoops can also be formedon the known heart valve stent which, together with the support arches,clamp parts of the old heart valve once the stent has unfolded to thatthe stent can be positioned and anchored as a result of this clampingaction.

Although the support arches provided on the anchoring stent enableimproved positioning of the heart valve prosthesis to be implanted,there is nevertheless still a risk of incorrect implantation and of theheart valve prosthesis being incapable of functioning correctly orfunctioning but unsatisfactorily. For example, it may be found duringthe intervention that the heart valve prosthesis or the heart valvestent is not optimally dimensioned for the patient. In such cases, evenif only the respective distal support or positioning arches of the stentare in their expanded state, removal (explantation) or repositioning ofthe heart valve stent with the heart valve prosthesis is no longerpossible and there exists an increased mortality risk for the particularpatient.

The aortic arch in the human body represents a further problem for suchinterventions, since it has to be accessed during insertion through theaorta. When this is done, the catheter tip and the respective cathetermust undergo a change of direction of approximately 180° over arelatively small radius, usually about 50 mm, without causing injury ordamage to the vessel wall.

The objective of the disclosure is to propose a catheter system forintroducing an expandable heart valve stent into the body of a patientand for positioning the stent at a desired implantation site, whereinthe catheter system is designed to enable the implantation of a heartvalve prosthesis attached to a heart valve stent in the optimumimplantation location in a sequence of events defined before theintervention.

Secondly, the objective is to propose a medical device for treatment ofa heart valve stenosis and/or heart valve insufficiency, comprising acatheter system and an expandable heart valve stent mounted in thecatheter tip of the insertion system and which is designed to reduce therisk to the patient on implantation of the heart valve prosthesis.

In accordance with a preferred embodiment, the present disclosureprovides a catheter system for introducing an expandable heart valvestent into the body of a patient, the catheter system comprising acatheter tip and a catheter shaft. The catheter tip of the cathetersystem has a seat portion for accommodating the stent to be introducedinto the patient's body in its collapsed state. The catheter system hasfurther a stent holder for realisably fixing the stent to the cathetertip. The seat portion of the catheter tip is constituted by a firstsleeve-shaped member and a second sleeve-shaped member, saidsleeve-shaped members being moveable relative to each other as well asrelative to the stent holder of the catheter tip. The catheter shaftcomprises first force transmitting means, second force transmittingmeans and guiding means. The distal end section of the first forcetransmitting means is connected to the first sleeve-shaped member of thecatheter tip and the proximal end section of the first forcetransmitting means is connectable to a first operating means of ahandle. The distal end section of the second force transmitting means isconnected to the second sleeve-shaped member of the catheter tip and theproximal end section of the second force transmitting means isconnectable to a second operating means of the handle.

Preferably, the cross-section of second sleeve-shaped member of thecatheter tip is equal to or less than the cross-section of the firstsleeve-shaped member of the catheter tip. In case the cross-section ofsecond sleeve-shaped member of the catheter tip is less than thecross-section of the first sleeve-shaped member, the secondsleeve-shaped member is at least partly accommodatable within the firstsleeve-shaped member in a telescopic manner. This may allow minimizingthe cross-section of catheter tip. At the same time, an expandable heartvalve stent may be released from the catheter tip of the catheter systemin a step-wise manner. In case the cross-section of second sleeve-shapedmember of the catheter tip is less than the cross-section of the firstsleeve-shaped member, the second sleeve-shaped member and the firstsleeve-shaped member—once brought together—can reside on an internalsupport structure, e.g. a cylindrical insert, resulting in a step andgap free transition.

According to one aspect of the present disclosure, the catheter systemcomprises guiding means having a guiding tube with a passagewayextending there between. The guiding means serves for guiding of thecatheter shaft has a distal end, a proximal end and a passagewayextending there between. The first and second force transmitting meansare at least partly received within this passageway such as to bemoveable relative to the guiding means. The guiding tube of the guidingmeans has a length such that the distal end of the guiding meansterminates proximal to the catheter tip of the catheter system.Moreover, guiding tube has a cross-section less than the cross-sectionof the catheter tip.

According to another aspect of the present disclosure, the cathetersystem further comprises a guide wire suited for guiding the cathetertip of the catheter system to an implantation site. The guide wire isdesigned to be advanced into a patient's vasculature independently fromthe catheter system and, in particular, independently from the cathetertip of the catheter system.

In accordance with another preferred embodiment, an insertion system forinserting an expandable heart valve stent is disclosed.

Whilst the term “vascular” refers to the blood vessels of the patient'sbody including both veins and arteries, in a preferred embodiment, theinsertion system is for transarterial delivery using the arteries,although it is conceivable that in other embodiments transvenousdelivery via a vein could be used.

In particular, the vascular insertion system comprises a catheter systemwith a catheter tip, a catheter shaft and a handle. The catheter tip hasa seat portion for accommodating a stent to be inserted in its collapsedstate and a stent holder for releasably fixing the stent. The proximalend of the catheter system is attached to the handle and the distal endis attached to the catheter tip. The catheter system comprises thecatheter shaft for connecting the catheter tip to the handle of theinsertion system, the distal end section of the catheter shaft beingflexible enough such that the catheter tip and the distal end section ofthe catheter shaft may be easily navigated through the anatomy andespecially through the aortic arch during insertion through the aorta ofthe patient.

The handle has at least one first and one second operating means withwhich the catheter tip of the insertion system may be appropriatelymanipulated so that an expandable stent housed in the catheter tip maybe released from the catheter tip in steps or in a defined or definablesequence of events.

The catheter tip of the catheter system and at least the distal part ofthe catheter shaft are typically inserted into the femoral artery andmoved up the descending thoracic aorta until the catheter tip ispositioned in the ascending aorta. The proximal end of the cathetershaft together with the handle attached thereto remains outside of thepatient's body.

In accordance with a preferred embodiment, the catheter tip has firstand second housing portions termed “sleeve-shaped members” in thefollowing, that may be manipulated with the handle. These sleeve-shapedmembers are used for accommodating specific portions of the stent. Thefirst sleeve-shaped member is used for accommodating first functionalcomponents of the stent, for example retaining hoops of the stent (oralternatively positioning hoops of the stent), while the secondsleeve-shaped member is used for accommodating the second functionalcomponents of the stent, for example, positioning hoops of the stent (oralternatively for accommodating retaining hoops of the stent).

In relation to the handle provided for the insertion system, it ispreferably provided that, on one hand, the first operating meanscooperate with the first sleeve-shaped member of the catheter tip sothat, on actuation of the first operating means, a previously definablelongitudinal displacement of the first sleeve-shaped member may beeffected relative to the stent holder and the guiding tube of thecatheter shaft. On the other hand, the second operating means cooperateswith the second sleeve-shaped member of the catheter tip so that apreviously definable longitudinal displacement of the secondsleeve-shaped member may be affected relative to the stent holder andthe guiding tube of the catheter shaft.

The cross-section of the second sleeve-shaped member is identical to thecross-section of the first sleeve-shaped member such that thesleeve-shaped members can completely enclose a stent accommodated in thecatheter tip without a gap between the first and second sleeve-shapedmembers thereby providing a catheter tip having an atraumatic shape. Inaddition, the first and second sleeve-shaped members are movablerelative to each other and relative to the stent holder.

For this purpose, first force transmitting means with a distal endsection connected to the first sleeve-shaped member and a proximal endsection connected to first operating means of the handle are provided.In addition, second force transmitting means with a distal end sectionconnected to the second sleeve-shaped member and a proximal end sectionconnected to second operating means of the handle are provided. Whenmanipulating the first and/or second operating means of the handle, thefirst and/or second sleeve-shaped members may be moved relative to eachother and relative to the stent holder.

In accordance with the preferred embodiment, the first forcetransmitting means is constituted by a first catheter tube defining afirst lumen and the second force transmitting means is constituted by asecond catheter tube defining a second lumen. The second catheter tubehas a cross-section less than the cross-section of the first cathetertube. The first catheter tube is disposed concentrically and coaxiallywith the second catheter tube and the second catheter tube is receivedwithin the first lumen defined by the first catheter tube.

Contrary to the first and second sleeve-shaped members of the cathetertip, however, the stent holder of the catheter tip is not moveablerelative to the handle of the insertion system. Rather, the stent holderis connected to the handle by using a stent holder tube having a distalend connected to the stent holder and a proximal end connected to a bodyof the handle. The stent holder tube has a cross-section less than thecross-section of the first catheter tube. In particular, the firstcatheter tube is disposed concentrically and coaxially with both, thesecond catheter tube on the one hand and the stent holder tube on theother hand. Preferably, the stent holder tube has a cross-section lessthan the cross-section of the first catheter tube and greater than thecross-section of the second catheter tube such that the stent holdertube is received within the first lumen defined by the first cathetertube and the second catheter tube is received within a passagewaydefined by the stent holder tube. The passageway defined by the stentholder tube has a diameter sufficient to accommodate the second cathetertube such that the second catheter tube is moveable relative to thestent holder tube.

The second lumen defined by the second catheter tube has a diametersufficient to accommodate a guide wire. The second catheter tube is madefrom a rigid material including, for example, nitinol, stainless steelor a rigid plastic material. The material of the distal end section ofthe second catheter tube may have an increased flexibility compared tothe material of the proximal end section in order to allow the distalend section of the catheter shaft to pass the aortic arch duringinsertion of the catheter tip.

The distal end section of the second catheter tube terminates in a softcatheter end tip having an atraumatic shape. The soft catheter end tipis provided with a channel aligned with the second lumen defined by thesecond catheter tube such that a guide wire accommodated within thesecond lumen of the second catheter tube may pass through the channel ofthe soft catheter end tip. The second sleeve-shaped member of thecatheter tip is connected to the soft catheter end tip such that theopened end of the second sleeve-shaped member faces in the proximaldirection opposite to the direction of the soft catheter end tip and tothe second catheter tube.

The stent holder tube is made of a rigid material, for example, a rigidplastic material, stainless steel or nitinol. The distal end of thestent holder tube terminates in the stent holder which is also made of arigid material, for example, a rigid plastic material or stainlesssteel. The passageway defined by the stent holder tube is aligned with achannel which passes through the stent holder. In this way, the secondcatheter tube is accommodated in the passageway of the stent holder tubeand the channel of the stent holder such as to be moveable relative tothe stent holder tube and the stent holder. The stent holder tube isprovided for connecting the stent holder to the handle. For thispurpose, the stent holder tube has a distal end connected to the stentholder and a proximal end connected to a body of the handle.

The first catheter tube is made of a bendable but inelastic material.For example, the first catheter tube may be at least partly made of abraided or non-braided catheter tube. Hence, the first catheter tube hasa stiff braid reinforced body similar to the catheter body described inU.S. Pat. No. 4,665,604 which is incorporated herein by reference.

The first catheter tube shall be adapted to transfer compression andtension forces from the first operating means of the handle to the firstsleeve-shaped member of the catheter tip without overly changing of itstotal length. The distal end of the first catheter tube terminates at aflared section as the transition to the section defining the firstsleeve-shaped member of the catheter tip. The flared section and thefirst sleeve-shaped member may be formed integrally and may be connectedto the distal end section of the first catheter tube. Alternatively, thefirst sleeve-shaped member and the flared section of the first cathetertube may be all of the same material and originating from the same rawtube prior to a widening process so that the flared section and thefirst sleeve-shaped member are the same elements.

The insertion system according to the preferred embodiment furthercomprises a guiding tube having a cross-section greater than thecross-section of the first catheter tube. The guiding tube defines apassageway and is disposed concentrically and coaxially with the firstcatheter tube, the stent holder tube and the second catheter tube suchthat the first catheter tube with the stent holder tube and the secondcatheter tube accommodated therein is at least partly accommodatedwithin the passageway defined by the guiding tube, wherein the firstcatheter tube is moveable relative to the guiding tube. In particular,the guiding tube terminates proximal to the catheter tip wherein thecross-section of proximal end section of the guiding tube shall besubstantially the same as or less than the cross-section of the flaredsection provided at the proximal end of the first catheter tube. Theproximal end section of the guiding tube terminates distal to thehandle. The proximal end section of the guiding tube may bedetached/disconnected from the handle so that the handle as well as thefirst and second catheter tubes and the stent holder tube together withcatheter tip may be moved relative to the guiding tube.

The distal end of the guiding tube is formed such that the flaredsection provided at the distal end section of the first catheter tubemay abut on the distal end of the guiding tube without abrupttransition. The guiding tube may be of a thin material such as to allowlength deformation of the guiding tube upon transfer of compression andtension forces. The guiding tube material, however, shall havesufficient stiffness in order to mechanically avoid kinking of theflexible sections of the distal portion of the catheter shaft duringinsertion of the catheter tip.

The proximal end of the guiding tube is releasably connectable to thebody of the handle. In this way, the guiding tube may have adouble-function:

In case, the proximal end of the guiding tube is connected to thehandle, the guiding tube serves as a distal extension of the body of thehandle relative to which the first and second operating means aremoveable for manipulating the first and second sleeve-shaped members ofthe catheter tip. Hence, position of the stent holder relative to thenative heart valve of the patient may be changed by moving the guidingtube connected to the handle.

In case, the proximal end of the guiding tube is not connected to thebody of the handle, the guiding tube may serve as a portal for passingthe catheter shaft of the catheter system into the patient's body fromproximal of the catheter tip.

In any case, the guiding tube has a length and is adapted such that thefirst catheter tube and the second catheter tube are moveable relativeto each other and relative to the stent holder independent from anymovement or activation of the guiding tube. In particular, the movementof the sleeve shaped members is independent from the presence or absenceof the guiding tube. The length of the guiding tube is such that thesleeved shaped members and hence the first and second catheter tubes aremoveable relative to each other and relative to the stent holder withoutinterfering with the distal end of the guiding tube.

An inlet may be provided at a proximal end section of the guiding tubefor injection of fluids into the guiding tube. Furthermore, a checkvalve may be provided at the proximal end section of the guiding tube toprevent fluid from leaking out of the guiding tube.

The guiding tube may have a length sufficient to protect the inner wallof the blood vessel through which the catheter tip passes. In addition,a separate introducer system (not belonging to the catheter system) maybe provided. The introducer system then may serve as a portal forpassing the complete catheter system from the catheter tip to thecatheter shaft into the patient's body and up to the heart.

In addition, the guiding tube reduces the compression force exerted onthe first catheter tube that is inserted through the guiding tube. Thisincreases manoeuvrabllity of the first catheter tube throughout theprocedure in which the first catheter tube serves as force transmittingmeans for manipulating the first sleeve-shaped member of the cathetertip. A consequence thereof is that the frictional force acting on thefirst catheter tube is reduced compared with a catheter design which isnot provided with a guiding tube. Moreover, moving the catheter tipafter it has been advanced through the vascular system of a patient, isgreatly improved while at the same time lowering the risk of injury ofthe patient.

In accordance with the preferred embodiment, the guiding tube has across-section equal to or less than the cross-section of the cathetertip. In this regard, the guiding tube will have a length shorter thanthe length of the first and second catheter tubes such that the distalend of the guiding tube terminates proximal to the catheter tip. As willbe appreciated, the guiding tube may not be removed from the cathetersystem in case the proximal end sections of the first and secondcatheter tube are connected to the respective operating means of ahandle.

The length of the guiding tube depends on the length of the first andsecond catheter tubes and will typically be between about 20 cm and 100cm. Those skilled in the art will appreciate, however, that alldimensions provided herein are intended as examples only, and that theguiding tubes and catheter tubes of different dimensions may besubstituted for a particular use. As already indicated, the first andsecond catheter tubes are moveable relative to each other and relativeto the stent holder independent from the guiding tube. The movement ofthe sleeve shaped members is independent from the presence or absence ofthe guiding tube. In other words, the guiding tube does not serve formanipulating the sleeve-shaped members of the catheter tip. Inparticular, the guiding tube does not block the travel of thesleeve-shaped members.

As will be appreciated, the guiding tube will be of a size, i.e. has anouter diameter, which will permit insertion in a patient's blood vessel(artery or vein) which is used for moving the stent transarterially orvia a vein to an insufficient heart valve.

The guiding tube may be capable of traversing tortuous pathways in thebody of the patient without kinking. The guiding tube may include aninner lubricious liner, an outer polymeric jacket, and a coilreinforcement between the inner and the outer layers. This guiding tubemay provide favourable flexibility without kinking or compression. Oneor more radiopaque bands or markers may be incorporated within theguiding tubes material to allow precise location of the guiding tubesdistal end for positioning accuracy. Those skilled in the art willappreciate that other known materials may also be suitable for aparticular purpose.

In an embodiment disclosed herein, the catheter tip and the cathetershaft proximally connected to the catheter tip may be inserted into thepatient's body by using a guide wire. The guide wire serves for guidingthe catheter tip of the catheter system to an implantation site. Once inposition above the aortic valve the guide wire may then be removed.Alternatively, the guide wire remains in the patient's body duringimplantation of a heart valve prosthesis accommodated in the cathetertip. Then, the guide wire is removed together with the catheter from thepatient's body.

The guide wire is designed to be advanced into a patient's vasculatureindependently from the catheter tip and the catheter shaft proximallyconnected to the catheter tip. In other words, the catheter tip togetherwith at least the distal part of the catheter shaft and the guide wireare advanced as single units through the vasculature of the patient,respectively. Once the guide wire is placed, the catheter tip and thecatheter shaft proximally connected to the catheter tip can be advancedover the guide wire directly to the particular site in the patient'scardiovascular system.

In accordance with the present invention, a guide wire is advancedthrough the patient's vascular system, its direction being controlledand fluoroscopically monitored by the surgeon, until its distal end isat the desired location. Preferably, the guide wire is very small indiameter, thereby not presenting any substantial obstruction to bloodflow in the blood vessel. After inserting the guide wire, the cathetertip together with the catheter shaft proximally connected to thecatheter tip are advanced over the guide wire with the wire beingreceived in the second lumen which is defined by the second cathetertube of the catheter shaft. The guide wire thus simply and automaticallyguides the catheter tip of the catheter system directly to the intendedregion, without requiring difficult, time consuming manipulations.

In a preferred embodiment of the present disclosure, the guide wire hasa diameter less than the diameter of the second lumen defined by thesecond catheter tube. This allows that the guide wire may be at leastpartly received within the second lumen defined by the second cathetertube for guiding the catheter tip, at least partly disposed about theguide wire, to the implantation site.

In a preferred embodiment of the invention, the second lumen defined bythe second catheter tube of the catheter shaft has a minimum dimensionwhich is just slightly greater than the diameter of the guide wire. Themaximum cross-sectional dimension of the second lumen is substantiallylarger than the cross-section of the guide wire. Thus, when the guidewire is disposed within the second lumen there will be substantial voidsthrough the second lumen, on opposite sides of the guide wire throughwhich fluids may be administered to the patient and through which bloodpressure measurements may be taken. Such fluids may be administered andpressure measurements may be taken without removing the guide wire atall. By way of example, the cross-section of the guide wire preferablyis of the order of no more than about fifty percent of thecross-sectional area of the second lumen.

In order to implant a heart valve prosthesis accommodated in thecatheter tip, the catheter tip and the catheter shaft proximallyconnected to the catheter tip are advanced over the guide wire. As thetip of the guide wire terminates in the left ventricle of the heart,pushing the guide wire may contact the left ventricular apex.

In order to avoid any damage of the left ventricular apex when the guidewire is inserted, and to avoid any injury or damage to the vessel wallwhen the guide wire inserted (advanced) through a vessel, the guide wirepreferably has a flexible bumper at the leading end of the advancingguide wire, which minimizes the risk of trauma or injury to the delicateinternal surfaces of the artery. The bumper is preferably highlyflexible and with a smooth leading end. For example, the guide wire mayterminate in a smoothly surfaced rounded tip, at the distal end of theguide wire. Alternatively, the distal end of the guide wire may have aj-hook shape or a hockey-stick shape, thereby reducing the risk oftrauma.

Since the guide wire and the catheter tip together with the cathetershaft proximally connected to the catheter tip are generallyindependently advanced into the vasculature, the guide wire must besufficiently stiff throughout its length to prevent buckling.Furthermore, the guide wire shall have sufficient stiffness to track thedelivery system (catheter tip and catheter shaft proximally connected tothe catheter tip) around the aortic arch. On the other hand, at leastthe distal tip of the guide wire shall be soft enough to preventpuncture of the heart tissue.

The guide wire may comprise a distal tip guide section and a proximalpull section. The pull section allowing for the tip guide section to bepulled out after final positioning of the catheter tip and having anoptimal cross sectional area and size, is generally smaller than that ofthe tip guide section so as to assure minimum blood leakage at theinsertion site. The tip guide section is capable of guiding the catheterthrough a patient's vasculature.

The guide wire may, in an exemplary embodiment, be approximately 175centimeters long so that it may be introduced through the femoral arteryand have ample length to reach the patient's coronary region. The guidewire may include a small diameter main wire. This rotationally rigidmain wire of the guide wire can be solid or tubular, as long as it isrigid torsionally so that it may transmit fully to the distal end arotational motion imparted to the proximal end. The main wire hasrelatively little twist as its proximal end is rotated. Practically allrotation applied to the proximal end will be transmitted quickly to thevery distal tip of the guide wire. Alternatively, the guide wire may beformed substantially from elongate helical springs.

As already indicated, the aortic arch in the human body may represent achallenge for transfemoral implantation of a self- or balloon-expandableheart valve stent with a heart valve prosthesis attached to it, since ithas to be accessed during insertion through the aorta. When this isdone, the catheter tip and the catheter shaft proximally connected tothe catheter tip must undergo a change of direction of approximately180° over a relatively small radius, usually about 50 mm, withoutcausing injury or damage to the vessel wall. For aiding the bending ofthe catheter tip and the catheter shaft proximally connected to thecatheter tip when passing through the aortic arch and for supporting thecatheter tip in accessing the ascending aorta, the guide wire may have aspecific structure such as to make a U turn in the aortic arch. Hence,the guide wire may be programmed such that the guide wire takes aU-shape bend.

In a preferred embodiment of the present disclosure, at least a distalsection of the guide wire has a predefined curved configuration adaptedto the curvature of the patient's aortic arch. The predefined curvedconfiguration of at least the distal section of the guide wire isselected such as to push the catheter tip in the direction of the centreof the ascending aorta when the catheter tip is at least partly disposedabout the distal section of the guide wire and transfemoral insertedinto the patient's body.

In this respect, the guide wire has a double-function: On the one hand,the guide wire serves for guiding the catheter tip of the cathetersystem to an implantation site. On the other hand, the guide wire servesfor positioning the catheter tip in the centre of the ascending aortawhen the catheter tip has accessed the ascending aorta. Then,positioning arches or hoops of the stent accommodated in the cathetertip may be easily inserted into the pockets of the native heart valve ofa patient so that the heart valve stent can be easily positioned.

In a preferred embodiment, at least the distal section of the guide wireexhibits a first predefinable shape before advancing the guide wire intothe patient's vasculature and a second predefinable shape in theadvanced state of said guide wire, wherein the second predefinable shapeof the distal section of the guide wire corresponds to the predefinedcurved configuration of the distal section of the guide wire. Forachieving this, the guide wire may consist at least partly of a shapememory material such that at least the distal section of the guide wirecan transform from a temporary shape into a permanent shape underinfluence of an external stimulus, wherein the temporary shape of thedistal section of the guide wire corresponds to the first shape and thepermanent shape of the distal section of the guide wire corresponds tothe second shape.

A shape memory material, for example Nitinol, may be used as thematerial for at least the distal section of the guide wire. Such a shapememory material is preferably designed such that the guide wire cantransform from a temporary shape into a permanent shape under theinfluence of an external stimulus. The temporary shape is thereby thefirst shape of the guide wire (i.e. the shape of the guide wire beforeinserting it into the patient's body), while the permanent shape isassumed in the second shape of the guide wire (I.e. In the insertedstate of the guide wire). In particular, use of a shape memory materialsuch as Nitinol, i.e. an equlatomic alloy of nickel and titanium, allowsfor a particularly gentle insertion procedure.

It is conceivable of course that other shape memory materials, forexample shape-memory polymers, are used as the material for at least thedistal section of the guide wire. At least parts of the guide wire maybe formed by using, for example, a polymer composite exhibiting acrystalline or semi-crystalline polymer network having crystallineswitching segments. On the other hand, an amorphous polymer networkhaving amorphous switching segments is also conceivable.

When manufacturing the guide wire preferably made from a shape memorymaterial, the permanent shape of the guide wire, i.e. the shape of theguide wire which is assumed in the inserted state of the guide wire, isformed. Once the desired shape has been formed, this shape is “fixed”,this process being known as “programming”. Programming may be effectedby heating the guide wire, forming the guide wire into the desired shapeand then cooling the guide wire. Programming may also be effected byforming and shaping the structure of the guide wire at lowertemperature, this being known as “cold stretching.” The permanent shapeis thus saved, enabling the guide wire to be stored and implanted in atemporary, non-formed shape. If an external stimulus then acts on thestent structure, the shape memory effect is activated and the saved,permanent shape restored.

A particularly preferred embodiment provides for the external stimulusto be a definable switching temperature. It is thus conceivable that thematerial of the guide wire needs to be heated to a higher temperaturethan the switching temperature in order to activate the shape memoryeffect and thus regenerate the saved permanent shape of the guide wire.A specific switching temperature can be preset by the relevant selectionof the chemical composition of the shape memory material.

It is particularly preferred to set the switching temperature to be inthe range of between 10° C. and the patient's body temperature andpreferably in the range of between 10° C. and room temperature (22° C.).Doing so is of advantage, especially with regard to the guide wire whichneeds to be inserted in a patient's body. Accordingly, all that needs tobe ensured in this regard when inserting the guide wire is that theguide wire is warmed up to room temperature or the patient's bodytemperature (37° C.) at the site of implantation to activate the shapememory effect of the stent material.

Alternatively, the guide wire may be made from another material (forexample a platinum-tungsten alloy) which allows that the distal regionof the guide wire can be bent manually by the surgeon and will retainits bent configuration when relaxed. This enables the guide wire to becontrollably steered by rotation of the guide wire to direct the curveddistal end selectively into the aortic arch and into the ascendingaorta. Rotational control of the guide wire may be enhanced by bendingthe proximal end of the wire to form somewhat of a handle.

In use, the surgeon may bend the distal region of the guide wire so thatit will be biased toward and will assume somewhat of a curve whenrelaxed. When advanced through the patient's artery the degree ofresilience at the distal region of the wire is such that the wire willstraighten and follow the path of the artery quite easily. Aprogressively increased flexibility resulting from, for example, acontinuous taper at the distal region of the guide wire may enhance theability of the guide wire to flex from the pre-bent biased curve andfollow the path of the blood vessel.

When the distal end of the pre-bent, biased guide wire is at thedescending aorta proximal of the aortic arch, the surgeon can steer itinto the aortic arch and thereafter into the ascending arch by rotationof the guide wire by manipulating it from the proximal end.

Alternatively, the guide wire may be inserted into the patient's body byusing a guide catheter. The guide catheter may comprise a guide cathetertube defining a lumen for receiving the guide wire. The guide cathetermay serve for inserting the guide wire. Once the guide catheter isintroduced through the femoral artery and the aortic arch and hasreached the patient's aortic valve region, the guide wire is releasedfrom the guide catheter by removing the guide catheter whereas the guidewire remains in the patient's body. In this case, the guide wireexhibits its first predefinable shape before releasing the guide wirefrom the guide catheter and its second predefinable shape afterreleasing the guide wire from the guide catheter. As already indicated,the second predefinable shape of the distal section of the guide wire isselected such that the distal section of the guide wire pushes thecatheter tip in the direction of the centre of the ascending aorta whenthe catheter tip is at least partly disposed about the distal section ofthe guide wire and transfemoral inserted into the patient's body.

According to one aspect of the present disclosure, at least the distalregion of the guide wire is at least partly formed from a materialhaving a high radiopacity. A relatively high degree of radiopacity ofthe distal region of the guide wire enhances fluoroscopic imaging of theguide wire as it is advanced through the patient's artery.

The procedure for using the guide wire in accordance with the presentinvention involves initial placement and location of the guide wire inthe femoral artery and the aortic arch. Once the guide wire is in placethe catheter tip with the catheter shaft of the catheter system then maybe advanced over the guide wire to a point where the stent accommodatedin the catheter tip is in the ascending aorta proximal to the nativeaortic heart valve. This can be verified fluoroscopically because of thehighly radiopaque characteristic of the catheter tip and/or guide wireand also by injecting radiopaque dye through, for example, a lumen ofthe catheter system. For this reason, the catheter tip of the cathetersystem may be provided with radiopaque markers which also facilitatefluoroscopic monitoring of its progress and position.

In order to treat a heart valve stenosis and/or heart valveinsufficiency in a patient, a medical device is disclosed. The medicaldevice comprises an insertion system and an expandable heart valve stentaccommodated in the catheter tip of the insertion system. While it isaccommodated in the catheter tip of the insertion system, the stentadopts a first previously definable configuration. Outside the cathetertip or in the implanted state, however, the stent exists in a secondpreviously definable configuration. The first configuration of the stentcorresponds to the folded-up state, while the stent exists in itsexpanded state in the second configuration.

A heart valve stent is used with the medical device, as described forexample in the European Patent Application No. 07 110 318 or in theEuropean Patent Application No. 08 151 963. In a preferred embodiment ofthe medical device, a heart valve stent is accordingly used whichexhibits the following:

-   -   a first retaining region, to which a heart valve prosthesis can        be attached;    -   an opposing, second retaining region with at least one retaining        element, for example in the form of retaining eyes or in the        form of retaining heads, whereby at least one retaining element        of the stent can be put in releasable engagement with the stent        holder of the catheter tip forming part of the insertion system;    -   at least one retaining hoop, to which a heart valve prosthesis        can be fastened; and    -   at least one and preferably three positioning hoops, which are        designed to engage in pockets of the native heart valve in the        implanted state of the stent, thus to enable automatic        positioning of the stent in the aorta of the patient.

In particular, an insertion system is proposed, with which an expandableheart valve stent with a heart valve prosthesis attached to this stentcan be advanced to the implantation site in a particularly simple way,for example via the aorta of a patient being treated (transarterially ortransfemorally). Preferably, during transarterial or transfemoral accessby the catheter system, the whole free cross-section available withinthe aorta is not completely filled up, since the catheter tip providedat the distal end region of the catheter system, in which the stent canbe accommodated with the heart valve prosthesis, can be madesufficiently small with respect to its external diameter.

The expandable heart valve stent with the heart valve prosthesisattached to it can be accommodated temporarily during implantation inthe folded-up state in the catheter tip of the insertion system, whichis provided at the distal end region of the catheter system. Thecatheter system may be of a length sufficient to allow the catheter tipprovided at the distal end region of the catheter system to be guidedthrough the aorta to the patient's heart by insertion at the patient'sgroin.

The insertion system designed for transarterial or transfemoral accessis therefore suitable for inserting a heart valve stent with a heartvalve prosthesis attached to it, transarterially or transfemorally intothe body of the patient; for example, the catheter system of theinsertion system is inserted with the catheter tip located at the distalend of the catheter system via puncture of the A. femoris communis(inguinal artery).

In particular, with the insertion system designed for transarterial ortransfemoral access, the catheter system may be designed so that it isboth kink-resistant and flexible such that a bending radius of up to 4cm, and preferably up to 3 cm, can be realised, at least at the distalend region of the catheter system.

Preferred embodiments will be described with reference to the appendeddrawings below.

Of these:

FIG. 1: an embodiment of an insertion system fortransfemoral/transarterial insertion of an expandable heart valve stentin a part-sectioned side elevation;

FIG. 2: an embodiment of a handle for an insertion system fortransfemoral/transarterial insertion of an expandable heart valve stentin a part-sectioned side elevation;

FIG. 3a : an embodiment of an insertion system fortransfemoral/transarterial insertion of a heart valve stent in a sideelevation;

FIG. 3b : a side elevation of the transfemoral/transarterial insertionsystem in accordance with FIG. 3a with a deflected catheter system;

FIG. 4: a further embodiment of an insertion system fortransfemoral/transarterial insertion of a heart valve stent in a sideelevation;

FIG. 5: a further embodiment of an insertion system fortransfemoral/transarterial insertion of a heart valve stent in a sideelevation;

FIG. 6a-d : side elevations of the transfemoral/transarterial insertionsystem in accordance with FIG. 3a in its four previously definedfunctional states to illustrate the loading procedure of the insertionsystem FIG. 7a-d : side elevations of the transfemoral/transarterialinsertion system in accordance with FIG. 3a in its four previouslydefined functional states to illustrate the release procedure of a stenthoused in the catheter tip of the insertion system;

FIG. 8: an embodiment of a catheter tip for an insertion system fortransfemoral/transarterial insertion of an expandable heart valve stentin a part-sectioned side elevation;

FIG. 9: a further embodiment of a catheter tip for an insertion systemfor transfemoral/transarterial insertion of an expandable heart valvestent in a part-sectioned side elevation;

FIG. 10a : an exemplary embodiment of a catheter shaft for an insertionsystem for transfemoral/transarterial insertion of an expandable heartvalve stent in a cross-sectional elevation;

FIG. 10b : a further exemplary embodiment of a catheter shaft for aninsertion system for transfemoral/transarterial insertion of anexpandable heart valve stent in a cross-sectional elevation;

FIG. 11: a schematic view to illustrate a transfemoral/transarterialimplantation procedure of a heart valve stent;

FIG. 12a-c : three-dimensional schematic part-sectioned view of thecatheter tip of a transfemoral/trans-apical insertion system indifferent functional states to illustrate the implantation procedure ofa heart valve stent mounted in the catheter tip;

FIG. 13a-d : side elevations of a further embodiment of a catheter tipfor an insertion system for transfemoral/transarterial insertion of anexpandable heart valve stent in its four previously defined functionalstates to illustrate the release procedure of a stent housed in thecatheter tip of the insertion system; and

FIG. 13e : a side elevation of the embodiment of a catheter tip inaccordance with FIG. 13a-d in its state after releasing a stent housedin the catheter tip and ready to be removed again from the body of thepatient.

FIG. 11 shows schematically an example of how a transarterial ortransfemoral access can be gained to the heart of a patient. In theillustration in accordance with FIG. 11, a heart valve stent 150 isadvanced with the aid of a insertion system 100 via the femoral arteryto the aortic valve. Embodiments of an insertion system 100, which issuitable for transarterial or transfemoral access, are described in thefollowing.

In accordance with a preferred embodiment, an insertion system 100 has acatheter system 1 and a handle 70 connected to the proximal end sectionof the catheter system 1. As depicted, for example, in FIG. 1, thecatheter system 1 of the preferred embodiment comprises a catheter tip10 having a seat portion for accommodating a stent to be inserted in itscollapsed state and a stent holder 15 for releasably fixing the stent.The catheter system 1 further comprises a catheter shaft 30 forconnecting the catheter tip 10 to the handle 70 of the insertion system100, the distal end section of the catheter shaft 30 being flexibleenough such that the catheter tip 10 and the distal end section of thecatheter shaft 30 may pass the aortic arch during insertion through theaorta of the patient.

The seat portion of the catheter tip 10 comprises a first sleeve-shapedmember 11 and a second sleeve-shaped member 21, the cross-section of thesecond sleeve-shaped member 21 are preferably identical to each othersuch that the first and second sleeve-shaped member 11, 21 cancompletely enclosed a stent accommodated in the catheter tip 10. Inaddition, the first and second sleeve-shaped members 11, 21 are movablerelative to each other and relative to the stent holder 15.

For this purpose, first force transmitting means 31 with a distal endsection connected to the first sleeve-shaped member 11 and a proximalend section connected to first operating means 71 of the handle 70 areprovided. In addition, second force transmitting means 41 with a distalend section connected to the second sleeve-shaped member 21 and aproximal end section connected to second operating means 81 of thehandle 70 are provided. When manipulating the first and/or secondoperating means 71, 81 of the handle 70, the first and/or secondsleeve-shaped members 11, 21 may be moved relative to each other andrelative to the stent holder 15.

As can be seen from FIG. 10a and FIG. 10b , the first force transmittingmeans 31 may be constituted by a first catheter tube 32 defining a firstlumen and the second force transmitting means 41 is constituted by asecond catheter tube 42 defining a second lumen. The second cathetertube 42 may have a cross-section less than the cross-section of thefirst catheter tube 32. The first catheter tube 32 may be disposedconcentrically and coaxially with the second catheter tube 42 and thesecond catheter tube 42 is received within the first lumen defined bythe first catheter tube 32.

Contrary to the first and second sleeve-shaped members 11, 21 of thecatheter tip 10, however, the stent holder 15 of the catheter tip 10 isnot moveable relative to the handle 70 of the insertion system 100.Rather, the stent holder 15 is connected to the housing 70′ of thehandle 70 by using a stent holder tube 62 having a distal end connectedto the stent holder 15 and a proximal end connected to a body 70′ of thehandle 70.

Referring to FIG. 10b , the stent holder tube 62 may have across-section less than the cross-section of the first catheter tube 32.In particular, the first catheter tube 32 may be disposed concentricallyand coaxially with both, the second catheter tube 42 on the one hand andthe stent holder tube 62 on the other hand. Preferably, the stent holdertube 62 has a cross-section less than the cross-section of the firstcatheter tube 32 and greater than the cross-section of the secondcatheter tube 42 such that the stent holder tube 62 is received withinthe first lumen defined by the first catheter tube 32 and the secondcatheter tube 42 is received within a passageway defined by the stentholder tube 62. The passageway defined by the stent holder tube 62 has adiameter sufficient to accommodate the second catheter tube 42 such thatthe second catheter tube 42 is moveable relative to the stent holdertube 62.

The second lumen defined by the second catheter tube 42 has a diametersufficient to accommodate a guide wire 180. The second catheter tube 42may be made from a rigid material including, for example, nitinol,stainless steel or a rigid plastic material (see FIG. 10b ). Thematerial of the distal end section of the second catheter tube 42 mayhave an increased flexibility compared to the material of the proximalend section in order to allow the distal end section of the cathetershaft 30 to pass the aortic arch during insertion of the catheter tip10. For example, the guiding tube 52 may be a 17F-catheter tube and thefirst catheter tube 32 may be a 12F-catheter tube.

As can been seen, for example, from FIG. 9, the distal end section ofthe second catheter tube 42 terminates in a soft catheter end tip 25having an atraumatic shape. The soft catheter end tip 25 is providedwith a channel aligned with the second lumen defined by the secondcatheter tube 42 such that a guide wire 180 accommodated within thesecond lumen of the second catheter tube 42 may pass through the channelof the soft catheter end tip 25. The second sleeve-shaped member 21 ofthe catheter tip 10 is connected to the soft catheter end tip 25 suchthat the opened end of the second sleeve-shaped member 21 faces in theproximal direction opposite to the direction of the soft catheter endtip 25 and to the second catheter tube 42.

According to the exemplary embodiment depicted in FIG. 10b , the stentholder tube 62 is made of a rigid material, for example, a rigid plasticmaterial, stainless steel or nitinol. The distal end of the stent holdertube 62 terminates in the stent holder 15 which is also made of a rigidmaterial, for example, a rigid plastic material or stainless steel. Thepassageway defined by the stent holder tube 62 is aligned with a channelwhich passes through the stent holder 15. In this way, the secondcatheter tube 42 is accommodated in the passageway of the stent holdertube 62 and the channel of the stent holder 15 such as to be moveablerelative to the stent holder tube 62 and the stent holder 15.

The first catheter tube 32 is made of a bendable but inelastic material.For example, the first catheter tube 32 may be at least partly made of abraided or non-braided catheter tube. The first catheter tube 32 shallbe adapted to transfer compression and tension forces from the firstoperating means 71 of the handle 70 to the first sleeve-shaped member 11of the catheter tip 10 without overly changing its total length. Thedistal end of the first catheter tube 32 terminates at a flared sectionas a transition to the section defining the first sleeve-shaped member11 of the catheter tip 10.

As can be seen from FIG. 9, the flared section and the firstsleeve-shaped member 11 may be formed integrally and may be connected tothe distal end section of the first catheter tube 31. In addition, theflared section may constitute the first sleeve-shaped member 11 of thecatheter tip 10. The first sleeve-shaped member 11 and the flaredsection of the first catheter tube 31 may be all of the same materialand originating from the same raw tube prior to a widening process sothat the flared section and the first sleeve-shaped member 11 are thesame elements.

Referring for example to FIG. 1, the insertion system 100 according tothe preferred embodiment further comprises a guiding tube 52 having across-section greater than the cross-section of the first catheter tube32. The guiding tube 52 defines a passageway and is disposedconcentrically and coaxially with the first catheter tube 32, the stentholder tube 62 and the second catheter tube 42 such that the firstcatheter tube 32 with the stent holder tube 62 and the second cathetertube 42 accommodated therein is at least partly accommodated within thepassageway defined by the guiding tube 52, wherein the first cathetertube 32 is moveable relative to the guiding tube 52. In particular, theguiding tube 52 terminates proximal to the catheter tip 10 wherein thecross-section of proximal end section of the guiding tube 52 shall bethe same as or less than the cross-section of the flared sectionprovided at the proximal end of the first catheter tube 32 so that asmooth transition from the first sleeve-shaped member 11 of the cathetertip 10 to the guiding tube 52 may be achieved (see FIG. 9).

The proximal end section of the guiding tube 52 terminates distal to thehandle 70. The proximal end section of the guiding tube 52 may bedetached/disconnected from the handle 70 so that the handle 70 as wellas the first and second catheter tubes 32, 42 and the stent holder tube62 together with catheter tip 10 may be moved relative to the guidingtube 52.

The distal end of the guiding tube 52 is formed such that the flaredsection provided at the distal end section of the first catheter tube 32may abut on the distal end of the guiding tube 52 without abrupttransition. The guiding tube 52 may be of a thin material such as toallow length deformation of the guiding tube 52 upon transfer ofcompression and tension forces. The material of the guiding tube 52,however, shall have sufficient stiffness in order to mechanically avoidkinking of the flexible sections of the distal portion of the cathetershaft 30 during insertion of the catheter tip 10.

The proximal end of the guiding tube 52 is releasably connectable to thebody 70′ of the handle 70. In this way, the guiding tube 52 may have adouble-function:

In case, the proximal end of the guiding tube 52 is connected to thehandle 70, the guiding tube 52 serves as a distal extension of the body70′ of the handle 70 relative to which the first and second operatingmeans 71, 81 are moveable for manipulating the first and secondsleeve-shaped members 11, 21 of the catheter tip 10. Hence, the positionof the stent holder 15 relative to the native heart valve of the patientmay be changed by moving the guiding tube 52 connected to the handle 70.

In case, the proximal end of the guiding tube 52 is not connected to thebody 70′ of the handle 70, the guiding tube 52 may serve as anintroducer tube, i.e. as a portal for passing the catheter tip 10 of thecatheter system 1 into the patient's body and up to the heart.

As depicted, for example, in FIG. 1, an inlet port 53 may be provided ata proximal end section of the guiding tube 52 for injection of fluidsinto the guiding tube 52. Furthermore, a check valve may be provided atthe proximal end section of the guiding tube 52 to prevent fluid fromleaking out of the guiding tube 52.

A description is given in the following, with reference to FIGS. 1 to 10b, of the components of exemplary embodiments of insertion systems 100,which are suitable for a transarterial or transfemoral access to theimplantation location. During a transarterial or transfemoral access,the catheter tip 10 of the insertion system 100 is advanced, forexample, via the aorta to the implantation site.

FIG. 1 shows a part-sectioned representation of an exemplary embodimentof an insertion system 100 designed for transfemoral or transarterialaccess.

As illustrated in FIG. 1, an insertion system 100 according to thepresent disclosure may comprise a catheter system 1 and a handle 70connected to the proximal end section of the catheter system 1. Thecatheter system 1 comprises a catheter tip 10 and a catheter shaft 30for connecting the catheter tip 10 to the handle 70. The catheter tip 10has a seat portion for accommodating a stent (see FIGS. 12a-c ) in itscollapsed state as well as a stent holder 15 for releasably fixing thestent.

The seat portion of the catheter tip 10 is constituted by a firstsleeve-shaped member 11 and a second sleeve-shaped member 21. As will beexplained in more detail with reference to FIGS. 6a-d and FIGS. 7a-d ,the sleeve-shaped members 11, 21 of the catheter tip 10 are movablerelative to each other and relative to the stent holder 15.

The catheter shaft 30 comprises first force transmitting means 31,second force transmitting means 41 and guiding means 51. In accordancewith the exemplary embodiment depicted in FIG. 1, the first and secondforce transmitting means 41 31, 41 of the catheter system 1 are realizedas flexible, elongated catheter tubes 32, 42. Each of the first andsecond catheter tubes 32, 42 defines a separate lumen. In addition, theguiding means 51 is realized as guiding tube 52 defining a passagewaywithin which the first and second catheter tubes 32, 42 are receivedsuch as to be movable relative to the guiding tube 52.

As can be seen in FIG. 1, the guiding tube 52 has a distal end whichterminates proximal to the catheter tip 10. On the other hand, the firstcatheter tube 32 has a length which is the same as, or substantiallysimilar to the length of the second catheter tube 42. The first cathetertube 32 terminates at its distal end in a flared section as a transitionto the section with wider cross-section defining the first sleeve-shapedmember 11 of the catheter tip 10. In particular, and as can be seen fromthe illustration in FIG. 9, the wider section of the first catheter tube32 is formed integrally with the distal end section of the firstcatheter tube 32. The wider section has a length greater than the lengthof a collapsed stent to be accommodated in the catheter tip 10.

As already mentioned, in the exemplary embodiment depicted in FIG. 1,the first force transmitting means 31 of the catheter system 1 isconstituted by a first catheter tube 32 defining a first lumen, whereinthe second force transmitting means 41 is constituted by a secondcatheter tube 42 defining a second lumen. The second catheter tube 42has a cross-section less than the cross-section of the first cathetertube 32, wherein the first catheter tube 32 is disposed concentricallyand coaxially with the second catheter tube 42. The cross-section of thecatheter tip 10, however, is greater than or equal to the cross-sectionof the guiding tube 52.

On the other hand, the guiding tube 52 has a cross-section which isgreater than the cross-section of the part of the first catheter tube 32which is received within the guiding tube 52. The cross-section of thecatheter tip 10, however, is greater than the cross-section of theguiding tube 52. Hence, the guiding tube 52 cannot be removed from theinsertion system 100 without disconnecting the catheter system 1 fromthe handle 70.

At the proximal end section of the guiding tube 52, a check valve may beprovided for preventing fluid from leaking out of the guiding tube 52.Furthermore, an inlet port 53 may be provided at the proximal endsection of the guiding tube 52 for injection of fluids into the guidingtube 52. Hence, fluids such as saline solution may be injected throughthe inlet port 52 to flush the interior passageway of the guiding tube52 and to reduce the incidence of blood dotting. A stopcock may beattached to the inlet port 53 to maintain the port 53 in a closedposition when the port 53 is not being accessed to flush the passagewayof the guiding tube 52.

The guiding tube 52 is movable relative to the handle 70 and the firstand second catheter tubes 32, 42. This provides a grip for the user whocan hold the catheter shaft 30 at its proximal end section duringpositioning of the catheter tip 10 and during manipulation of thesleeve-shaped element 11 of the catheter tip 10. The user can hold theguiding tube 52, and in particular the proximal end section of theguiding tube 52 for supporting the movement of the first sleeve-shapedelement 11 of the catheter tip 10 relative to the handle 70 such thatthe outer sheath of the catheter system 1 need not be held by the useror kinked.

In the exemplary embodiment of the insertion system 100 depicted in FIG.1, a handle 70 is utilized, said handle 70 comprising first and a secondoperating means 71, 81, which are connected by means of correspondingfirst and second force transmission means 31, 41 of the catheter shaft30 to the first and second sleeve-shaped member 21 s 11, 21 of thecatheter tip 10. The first operating means 71 has a first pusher 73which is functionally connected to the first slide 74. The first slide74 is guided in a first guide 72 in the longitudinal direction L of thehandle 70. The distal-side end of the first guide 72 defines the firststop 75 and the proximal-side end of the first guide 72 the second stop76, which define the overall longitudinal displacement that can beeffected with the first operating means 71. A locking element 77′ may bepositioned between the distal-side and the proximal-side end of thefirst guide 72, which defines the additional stop 77.

The second operating means 81 of the handle 70 shown in FIG. 1 has asecond pusher 83, which is functionally connected to a second slide 84.The second slide 84 is guided in a longitudinal guide (second guide 82)between a first stop 85 and a second stop 86. The second slide 84 isconnected by means of the second force transmission means 41 with thesecond sleeve-shaped member 21 of the catheter tip 10. On actuation ofthe second operating means 81, the second slide 84 is moved in thelongitudinal direction L of the handle 70 from the first stop 85 to thesecond stop 86. This movement effects a longitudinal displacement of thesecond sleeve-shaped member 21 of the catheter tip 10 connected via thesecond force transmission means 41 with the second operating means 81.

To prevent an unintended displacement of the second slide 84, the secondoperating means 81 is equipped with a securing element 89, which mayconnect the second slide 84 with the body 70′ of the handle 70 when inuse. A longitudinal displacement of the second slide 84 to the secondstop 86 is possible following removal or deactivation of the securingelement 89.

FIG. 2 shows a further embodiment of a handle 70 of an insertion system100 designed for transfemoral or transarterial access in apart-sectioned side view. The construction and mode of operation of thefirst and second operating means 81 71, 81 of the embodiment of thehandle 70 shown in FIG. 2 is comparable in structural and functionalrespects to the handle 70 as previously described with reference toFIG. 1. Hence, elements in FIG. 2 that are generally similar topreviously described elements have the same reference numbers comparedwith the reference numbers in FIG. 1 previously used for the similarelements.

In distinction to the handle 70 described with reference to FIG. 1,however, the handle 70 in accordance with FIG. 2 is provided with athird operating means 96 in the form of a wheel, by means of which aflexural link region 34 of the catheter shaft 30 can be controlled. Itis important to note, however, that the catheter shaft 30 is onlyoptionally provided with such flexural link region 34. Rather, thematerial of the distal end section of the catheter shaft 30 may have anincreased flexibility compared to the material of the proximal endsection in order to allow the distal end section of the catheter shaftto pass 30 the aortic arch during insertion of the catheter tip.

In the exemplary embodiment depicted in FIG. 2, the third operatingelement 96 preferably has a detent device 100, to allow a set deflectionof the flexural link region 34 of the catheter shaft 30 to be fixed. Forexample, it is possible to provide a suitable catch mechanism on thehand wheel of the third operating means 96, which cooperates with thebody 70′ of the handle 70. In particular, it is possible for theflexural link region 34 of the catheter shaft 30 to be connected to thethird operating means 96 by way of a control wire 35 whereby, on anactuation of the third operating means 96 via the control wire 35 atensile forces is exerted on the flexural link region 34, which producesthe deflection of the flexural link region 34 (see FIG. 3b ).

However it is also possible, of course, to choose another embodiment asthe third operating means 96 for deflecting a flexural link region 34 ofthe catheter shaft 30, in case the catheter shaft 30 is provided withsuch a flexural link region 34.

The handle 70 of the insertion system 100 designed for transarterial ortransfemoral access may be provided with a pretensioning device, shownin FIG. 2. With such a pretensioning device, a constant tensile forcemay be exerted via the second operating means 81 on the secondsleeve-shaped member 21 of the catheter tip 10. As shown in FIG. 2, thepretensioning device may have a compression spring 97, permanentlystressed along its spring axis, which is prestressed between a firststop 97 a connected to the body 70′ of the handle 70 and a second stop97 b connected to the proximal end region of the second operating means81. In this respect, a permanent, previously defined or definabletensile force is exerted on the second sleeve-shaped member 21 of thecatheter tip 10.

The pretensioning device implemented with the spring 97 in theembodiment in accordance with FIG. 2 may be advantageous when thecatheter shaft 30 is bent during the implantation procedure, forexample, when the catheter tip 10 of the insertion system 100 isinserted through the aorta. When the catheter shaft 30 is bent, theouter fibres of the catheter shaft 30 are shortened. This can becompensated appropriately with the aid of the pretensioning device. Indetail, on bending of the fiexural link region 34 relative to theneutral fibres of the catheter shaft 30 running along the longitudinalaxis L, the outer fibres of the catheter shaft 30 radially spaced fromthe neutral fibres are shortened. Since the second force transmissionmeans 41, which connects the second operating means 81 with the secondsleeve-shaped member 21 in the insertion system 100, normally runs alongthe neutral fibre of the catheter shaft 30, a bending contractioninevitably occurs when the catheter shaft 30 is bent, having the resultthat, despite fixing of the first operating means 71, the firstsleeve-shaped member 11 of the catheter tip 10 is displaced relative tothe stent holder 15 in a proximal direction.

This longitudinal displacement of the first sleeve-shaped member 11 ofthe catheter tip 10 that takes place during the bending procedure iscompensated with the aid of the prestressing device (spring 97), sincethe spring 97 of the prestressing device exerts a constant tensile forceon the second force transmission means 41 and therefore on the secondsleeve-shaped member 21 of the catheter tip 10 and consequentlyconstantly presses the distal-side end tip 25 of the catheter tip 10against the distal-side end of the first sleeve-shaped member 11. Thisenables the catheter tip 10 to remain completely closed even during adeflection of the catheter shaft 30 effected, for example, when thecatheter tip 10 is inserted through the aorta.

On actuation of the second operating means 81 of the handle 70, it isnecessary to press the second slide 84 against the prestress supplied bythe spring 97 of the prestressing device on the second stop 86.

It is important to note, however, that a prestressing device of the kindas described above is not mandatory for the insertion system asdisclosed herein.

A further exemplary embodiment of an insertion system 100 designed fortransarterial/transfemoral access is shown in FIGS. 3a, b . Elements inFIGS. 3a, b that are generally similar to previously described elementshave the same reference numbers compared with the reference numbers inFIGS. 1 and 2 previously used for the similar elements.

The insertion system 100 shown in FIGS. 3a, b comprises a cathetersystem 1 of the kind as previously described with reference to FIG. 1,i.e. a catheter system 1 having a catheter tip 10 and a catheter shaft30 which is provided with a first catheter tube 32 acting as first forcetransmitting means 31, a second catheter tube 42 acting as second forcetransmitting means 41, and a guiding tube 52 acting as guiding means 51.Contrary to the catheter shaft 30 utilized in the exemplary embodimentof the insertion system 100 depicted in FIG. 1, however, the cathetershaft 30 of the insertion system 100 shown in FIGS. 3a, b is providedwith a flexural link region 34 of the kind as previously described withreference to FIG. 2.

As will be described in the following, the insertion system 100 shown inFIGS. 3a, b is provided with a different embodiment of a handle 70 whichis used in order to manipulate the first and second sleeve-shapedmembers 11, 21 of the catheter tip 10.

In relation to the handle 70 used with the insertion system 100 shown inFIG. 3a , it can be seen that the end region of the handle 70 is in theform of a turning mechanism 98 (rotatable means), with which the secondforce transmission means 41 of the catheter shaft 30 can be twisted withthe distal-side end tip 25 and the second sleeve-shaped member 21 of thecatheter tip 10 fastened to it about the longitudinal axis L of thecatheter tip 10. The second sleeve-shaped member 21 of the catheter tip10 is connected by means of a loose bearing to the stent holder 15,allowing transmission of a turning moment between the secondsleeve-shaped member 21 and the stent holder 15, without allowingtransmission of any tensile or compression forces acting in thedirection of the longitudinal axis L of the catheter tip 10. Thus, whena turning movement of the second sleeve-shaped member 21 is induced withthe turning mechanism 98, the stent holder 15 also turns correspondinglyabout the longitudinal axis L.

The turning mechanism 98 preferably allows the stent holder 15 to twistthrough approximately 120°. Thus the rotation of a stent housed in thecatheter tip 10, and particularly the positioning hoops already releasedin the second functional state of the insertion system 100, can becontrolled, facilitating precise positioning of the already expandedpositioning hoops of the stent in the pockets of the insufficient,native heart valve.

Preferably, the rotation movement of the stent holder 15 about thelongitudinal axis L of the catheter tip 10 that can be effected with theturning mechanism 98 exhibits a previously definable, preferably smalldelay in reaction to a turning moment initiated by means of the turningmechanism 98.

Further, the embodiment of the handle 70 shown in FIG. 3a is equippedwith a third operating means 96 in the form of a wheel, with which aflexural link 34, preferably provided at the distal end region of thecatheter shaft 30, can be deflected.

The deflection of the distal end region of the catheter shaft 30 thatcan be effected with this flexural link region 34 is shown schematicallyin FIG. 3b . In detail, a device is provided for force transmission(control wire 35—see FIG. 8) which is connected on one side to theflexural link regions 34 preferably provided at the distal end region ofthe catheter shaft 30 and, on the other side, to the third operatingmeans 96 of the handle 70 implemented in the embodiment shown in FIG. 3as a hand wheel.

It is possible to implement the device for force transmission as acontrol wire 35, which is passed through the inside of the firsttransmission means 31 and preferably at the distal end of the flexurallink region 34 or at the proximal end of the catheter tip 10 (see FIG.8) to have a directed effect on the curvature of the flexural linkregion 34. With the tensile forces that can be exerted on the flexurallink region 34 with the aid of the control wire 35, it is possible toobtain a defined curvature of the distal end region of the cathetershaft 30. This is a particular advantage duringtransarterial/transfemoral access when navigating the aortic arch.

Further exemplary embodiments of an insertion system 100 which issuitable for transarterial/transfemoral access to the implantationlocation are shown in FIGS. 4 and 5. Elements in FIGS. 4 and 5 that aregenerally similar to previously described elements have the samereference numbers compared with the reference numbers in FIGS. 1, 2 and3 a, b previously used for the similar elements.

Compared with the exemplary embodiment depicted in FIGS. 1 and 2 as wellas FIGS. 3a, b , the embodiments shown in FIGS. 4 and 5 differ first andforemost in relation to the implementation of the correspondingoperating means 71, 81 of the handle 70.

The insertion system 100 in accordance with FIG. 4 has a handle 70 withwhich the first operating means 71, which is used for manipulation ofthe first sleeve-shaped member 11 of the catheter tip 10, is similar toa trigger of a revolver. The user such as a physician who carries outthe treatment may hold the handle 70 at the grip 88, while the firstoperating means 71 in the form of a trigger of a revolver is operatedwith the index finger of the hand holding it.

In the insertion system 100 shown in FIG. 5, a handle 70 is used whichcorresponds in structural and functional respects to the handle 70 usedwith the insertion system 100 in FIG. 3 with the exception of the grip88 provided in the embodiment in accordance with FIG. 3.

A description is given in the following, with reference to FIGS. 6a-dand FIGS. 7a-d , of the functional coaction of the components of aninsertion system 100, which is suitable for a transarterial ortransfemoral access to the implantation location. Elements in FIGS. 6ato 6d and FIGS. 7a to 7d that are generally similar to previouslydescribed elements have the same reference numbers compared with thereference numbers in FIGS. 1 to 5 previously used for the similarelements.

Reference is made to FIGS. 6a to 6d for illustrating the procedure forloading a stent into the catheter tip 10 of the insertion system 100. InFIGS. 7a to 7d , the stepwise release of a stent mounted in the cathetertip 10 of the insertion system 100 is illustrated.

It is important to note, however, that the procedure for loading a stentinto the catheter tip 10 as depicted in FIGS. 6a to 6d , as well as theprocedure for stepwise releasing of a stent mounted in the catheter tip10 as depicted in FIGS. 7a to 7d also apply to the other exemplaryembodiments of the transarterial/transfemoral insertion system 100disclosed herein.

The handle 70 for the transarterial/transfemoral insertion system 100according to the illustration in FIGS. 6 and 7 has a wheel rotatablymounted in the handle 70 which is functionally connected to the firstsleeve-shaped member 11 of the catheter tip 10 associated with the firstoperating means 71 via a corresponding first force transmission means31, so that force can be directly transmitted from the first operatingmeans 71 in the form of the wheel to the first sleeve-shaped member 11of the catheter tip 10.

In detail, it is provided that, with the first operating means 71 of thehandle 70 in accordance with FIG. 6 and FIG. 7, the first operatingmeans 71 in the form of the wheel can turn between a first stop and asecond stop, in order to execute a definable longitudinal displacementstroke on the first sleeve-shaped member 11 of the catheter tip 10. Thefirst operating means 71 of the handle 70 is provided with a additionalstop between the first and second stop which cooperates, on one sidewith the first stop and on the other up with the second stop so that, onactuation of the first operating means 71, a longitudinal displacementof the first sleeve-shaped member 11 of the catheter tip 10 can beeffected relative to the stent holder 15 of the catheter tip 10,consisting of two defined separate steps.

With the first operating means 71 used in the form of a wheel, theadditional stop associated with the first operating means 71 is in theform of a locking element 77′ positioned removably in the flow of forcebetween the wheel and the first sleeve-shaped member 11 of the cathetertip 10, interrupting direct force transmission from the wheel to thefirst sleeve-shaped member 11 of the catheter tip 10. Alternatively,however, it is possible for the additional stop associated with thefirst operating means 71 to be in the form of a locking elementrestricting the free rotation of the wheel between the first and thesecond stop.

However, it is of course also possible in principle for the firstoperating means 71 of the handle 70 used with the insertion system 100designed for transarterial/transfemoral access not to be a wheel, but tobe implemented as a pusher mechanism.

In relation to the handle 70 that is used with the embodiment of theinsertion system 100, for example in accordance with the illustrationsin FIGS. 6 and 7, it is provided that the second operating means 81 hasa second slide 84 guided in a second guide 82 and functionally connectedto a second pusher 83. This second slide 84, which is guided in theinterior of the handle 70 and therefore cannot be seen in the view ofFIGS. 6 and 7, is functionally connected to the second sleeve-shapedmember 21 of the catheter tip 10 associated with the second operatingmeans 81 by means of a second force transmission means 41 so that, onactuation of the second operating means 81, force is directlytransmitted from the second slide 84 to the second sleeve-shaped member21 of the catheter tip 10.

The second operating means 81 can be displaced between a first position(Pos. 1) and a second position (Pos. 2) in the longitudinal direction ofthe handle 70, whereby the longitudinal displacement stroke that can bethus effected via the second force transmission means 41 is transferreddirectly to the second sleeve-shaped member 21 of the catheter tip 10.The first and second positions are each defined with the aid of a firstand a second stop 85, 86.

A securing element 89 is provided, associated with the second operatingmeans 81, which is removably located on the second guide 82 and whichblocks longitudinal displacement of the (second) slide 84 associatedwith the second operating means 81 when used.

The handle 70 which is used with the transarterial/transfemoralinsertion system 100 of the embodiment shown in FIGS. 6 and 7 furtherexhibits an optional grip 88, which facilitates the operability of thehandle 70 and in particular the operating conformity of the handle 70.The grip 88 is preferably releasably connected to the body 70′ of thehandle 70 and can optionally be fixed at different positions on the body70′ of the handle 70.

In relation to the construction of the catheter tip 10 which is used,for example, with the insertion system 100 shown in FIGS. 6 and 7 andwhich allows transarterial/transfemoral access of a stent housed in thecatheter tip 10 to the implantation location, it can be seen from FIGS.6 and 7 that the catheter tip 10 has a stent holder 15 for releasablyfixing of, for example, the second retaining region of a stent that canbe housed in the catheter tip 10. The retaining elements 16 of the stentholder 15 in the form of a crown are provided at the proximal end of thestent holder 15.

Further, the catheter tip 10 of the insertion system 100 designed fortransarterial/transfemoral access comprises a mounting device formounting a heart valve stent, where required, with a heart valveprosthesis fastened to it. In detail, the mounting device of thecatheter tip 10 consists of a first sleeve-shaped member 11,particularly for accommodating the positioning hoops of a stent, and asecond sleeve-shaped member 21, in particular for accommodating theheart valve prosthesis fastened to it, when required.

The first operating means 71 of the handle 70 co-operates in theembodiment according to FIGS. 6 and 7 with the first sleeve-shapedmember 11 of the catheter tip 10 so that, on actuation of the firstoperating means 71, by transfer of a defined longitudinal displacementstroke, a previously definable longitudinal displacement of the firstsleeve-shaped member 11 can be effected relative to the stent holder 15.On the other hand, with the insertion system 100 according to FIGS. 6and 7, the second operating means 81 of the handle 70 co-operates withthe second sleeve-shaped member 21 of the catheter tip 10 so that, onactuation of the second operating means 81, by transfer of a definedlongitudinal displacement stroke, a previously definable longitudinaldisplacement of the second sleeve-shaped member 21 of the catheter tip10 relative to the stent holder 15 can be effected.

The second sleeve-shaped member 21, which is used to house the retaininghoops of the stent with, where required, the heart valve prosthesisfastened to them, is located at the distal end region of the cathetertip 10, while the first sleeve-shaped member 11 is located between thesecond sleeve-shaped member 21 and the handle 70.

In the insertion system 100 shown in FIGS. 6 and 7, the second forcetransmission means 41, which connects the second operating means 81 ofthe handle 70 to the second sleeve-shaped member 21 of the catheter tip10, is preferably in the form of an inner catheter running inside theinterior of the catheter or tube system. The first force transmissionmeans 31, which connects the first operating means 71 of the handle 70to the first sleeve-shaped member 11 of the catheter tip 10, is in theform of an outer catheter, in the interior of which the first forcetransmission means 31 runs in the form of the inner catheter.

On actuation on the second operating means 81, the second sleeve-shapedmember 21 can be moved relative to the stent holder 15 in thelongitudinal direction L of the catheter tip 10 in a distal direction,thus away from the handle 70, while, on actuation of the first operatingmeans 71 of the handle 70, the first sleeve-shaped member 11 of thecatheter tip 10 can be moved relative to the stent holder 15 in thelongitudinal direction L of the catheter tip 10 in a proximal direction,and thus towards the handle 70.

The manipulations of the respective sleeve-shaped members 11, 21 of thecatheter tip 10 that can be effected on actuation of the respectiveoperating means 71, 81 with the insertion system 100 of 100 designed fortransarterial/transfemoral access in accordance with FIGS. 6 and 7 aredescribed in detail in the following, with reference in particular toFIGS. 7a to 7 d.

An embodiment of a transarterial/transfemoral insertion system 100 isshown in its four different functional states in FIGS. 7a to 7d . Indetail, the insertion system 100 is shown in its first functional statein FIG. 7a , in which the catheter shaft 30 with the catheter tip 10and, where required, with the stent accommodated in it can be insertedinto the patient transarterially or transfemorally and advanced via theaorta to the implantation site.

In the first functional state of the insertion system 100 in accordancewith FIG. 7a , the catheter tip 10 is completely closed, whereby the twosleeve-shaped members 11, 21 of the catheter tip 10 overlaptelescopically. The respective diameters of the sleeve-shaped members11, 21 are chosen so that the folded-up retaining hoops of a stent, withthe heart valve prosthesis fastened to them where required, can behoused in the second sleeve-shaped member 21. The folded-up positioninghoops of the stent housed between the second sleeve-shaped member 21 andthe first sleeve-shaped member 11 are held together in their foldedform.

The second retaining region of the stent is shown in the firstfunctional state of the insertion system 100, as shown in FIG. 7a , withthe stent holder 15 fixed at the proximal end of the catheter tip 10.For this purpose, the retaining elements (retaining rings etc.) providedat the second retaining region of the stent are engaged with retainingelements 16 of the stent holder 15.

The retaining elements 16 of the stent holder 15 are covered by thefirst sleeve-shaped member 11 of the catheter tip 10 in the firstfunctional state shown in FIG. 7a , so that an engagement betweenretaining elements provided on the second retaining region of a stentand retaining elements 16 of the stent holder 15 would be possible.

The first functional state of the insertion system 100 shown in FIG. 7ais maintained during the transarterial insertion procedure. On reachingthe implantation location, the insertion system 100 is transferred fromthe first functional state shown in FIG. 7a to the second functionalstate shown in FIG. 7b , by transferring the first operating means 71(shown in the embodiment of the wheel in FIG. 7) from the first positioninto the second position. The longitudinal displacement stroketransferred by actuation of the first operating means 71 to the firstsleeve-shaped member 11 of the catheter tip 10 effects a displacement ofthe first sleeve-shaped member 11 relative to the stent holder 15 in theproximal direction, thus towards the handle 70.

The longitudinal displacement stroke executed on the first sleeve-shapedmember 11 of the catheter tip 10 during the transition from the firstfunctional state (see FIG. 7a ) to the second functional state (see FIG.7b ) by the first operating means 71 of the handle 70 via acorresponding first force transmission means 31 is previously defined sothat the first sleeve-shaped member 11 is displaced relative to thestent holder 15 in the proximal direction just so far that thepositioning hoops of a stent housed in the catheter tip 10 would bereleased, though the distal end of the first sleeve-shaped member 11 ofthe catheter tip 10 would still cover the retaining elements 16 of thestent holder 15, so that the engagement between the retaining elementsprovided at the second retaining region of the stent and the retainingelements 16 of the stent holder 15 would be secure.

Since the second sleeve-shaped member 21 is not manipulated during thetransition from the first functional state into the second functionalstate, the first retaining region of a stent housed in the catheter tip10 with the heart valve prosthesis fastened to it would continue to behoused in its folded together state in the sleeve-shaped element of thesecond sleeve-shaped member 21.

The positioning hoops of a stent housed in the catheter tip 10 releasedin the second functional state of the insertion system 100 are opened asa result of the radial forces acting on them and can thus be positionedin the pockets of the insufficient native heart valve. Followingappropriate positioning of the positioning hoops of the stent in thepockets of the native heart valve, the insertion system 100 istransferred from the second functional state shown in FIG. 7b into thethird functional state shown in FIG. 7c . This is done my manipulationof the second operating means 81, after the securing element 89associated with the second operating means 81 has been removed.

On actuation of the second operating means 81, the second sleeve-shapedmember 21 of the catheter tip 10 associated with the second operatingmeans 81 is moved relative to the stent holder 15 by a previouslyestablished longitudinal displacement stroke defined with the secondoperating means 81 in a distal direction, thus away from the handle 70.The longitudinal displacement stroke acting on the second sleeve-shapedmember 21 is chosen so that the sleeve-shaped member 21 no longer coversthe first retaining region of a stent housed in the catheter tip 10 withthe heart valve prosthesis fastened to it, where required, and thusreleases the first retaining region of the stent. Due to the action ofthe radial forces, the distal retaining region of the stent with theheart valve prosthesis attached to it, where required, unfoldscompletely.

Since the first operating means 71 of the handle 70 and the associatedfirst sleeve-shaped member 11 of the catheter tip 10 are not manipulatedduring the transition from the second functional state in accordancewith FIG. 7b into the third functional state in accordance with FIG. 7c, the distal end region of the first sleeve-shaped member 11 continuesto cover the retaining elements 16 of the stent holder 15, so that theengagement between the retaining elements of a stent housed in thecatheter tip 10 and the retaining elements 16 of the stent holder 15 issecure and the proximal retaining region of the stent is in itsfolded-up state. This anchorage of the stent to the catheter tip 10 ofthe insertion system 100 allows an explantation of a stent that isalready partially unfolded by returning the insertion system 100 fromthe third functional state, by appropriate manipulation of the secondoperating means 81 of the handle 70, to the second functional state andthen by suitable actuation of the first operating means 71 transfer tothe first functional state.

If an explantation of the stent with the heart valve prosthesis attachedto it, where required, is unnecessary, the insertion system 100 istransferred from the third functional state shown in FIG. 7c into thefourth functional state shown in FIG. 7d , by turning the firstoperating means 71 of the handle 70 further from the second position tothe third position after removal of the securing element 79 (lockingelement). This manipulation of the first operating means 71 that can beeffected after removal of the securing element 79 results in a furtherdefined movement of the first sleeve-shaped member 11 relative to thestent holder 15 of the catheter tip 10 in a proximal direction, thustowards the handle 70. The longitudinal displacement stroke executed onthe first sleeve-shaped member 11 is chosen so that the distal end ofthe first sleeve-shaped member 11 no longer covers the retainingelements 16 of the stent holder 15, as a result of which an engagementbetween the retaining elements of a stent housed in the catheter tip 10and the retaining elements 16 of the stent holder 15 can be released,which would also lead to a complete release of the second retainingregion of the stent and a complete separation of the stent from thecatheter tip 10 and correspondingly to a complete unfolding of thestent.

The four functional states of the insertion system 100 designed fortransarterial/transfemoral access, previously described with referenceto FIGS. 7a to 7d , are shown in reverse order in FIGS. 6a to 6d toclarify the procedure for loading a stent into the catheter tip 10 ofthe insertion system 100. Comparison between FIGS. 6a to 6d and FIGS. 7ato 7d show that the insertion system 100 can be loaded with a heartvalve stent by transferring the insertion system 100, starting from itsfourth functional state in accordance with FIG. 6a (see FIG. 7d ), intoits third functional state in accordance with FIG. 6b (see FIG. 7c )after a stent has been positioned between the stent holder 15 on thesecond sleeve-shaped member 21 with its first retaining region in thedirection of the second sleeve-shaped member 21. Then the remainingfunctional states of the insertion system 100 are taken up in stepsuntil the insertion system 100 shown in FIG. 6d is finally in its firstfunctional state with the closed catheter tip 10.

Reference is made to FIG. 9 for describing an exemplary embodiment ofthe catheter tip 10. Elements in FIG. 9 that are generally similar topreviously described elements have the same reference numbers comparedwith the reference numbers in FIGS. 1 to 7 previously used for thesimilar elements.

An exemplary embodiment of a catheter shaft 30 is described in thefollowing, with reference to the illustration in FIG. 9. This cathetershaft 30 can be used with an insertion system 100 designed fortransarterial or transfemoral access.

In detail, FIG. 9 shows an exemplary embodiment of a shaft for aninsertion system 100 in a cross-sectional elevation.

The catheter shaft 30 exhibits a first force transmission means 31 inthe form of a first catheter tube 32, whereby this first catheter tube32 is used to connect the first operating means 71 of the handle 70 tothe first sleeve-shaped member 11 of the catheter tip 10. As can be seenin particular from the illustration in FIG. 1, the first forcetransmission means 31 implemented as a first catheter tube 32 may beclamped between a screw cap 74′ and the first slide 74 of the firstoperating means 71 and consequently is permanently connected to thefirst slide 74. The distal-side end region of the first catheter tube 32merges into the first sleeve-shaped member 11 of the catheter tip 10 inthe form of the stent sheath.

The second force transmission means 41 of the catheter shaft 30 usedwith an insertion system 100 designed for transarterial or transfemoralaccess is preferably implemented as a second catheter tube 42. Theproximal-side end region of the second catheter tube 42 is connected tothe second operating means 81 of the handle 70. The distal-side endregion of the second catheter tube 42 is connected to the catheter endtip 25 of the catheter tip 10. The second sleeve-shaped member 21 of thecatheter tip 10 is permanently connected by means of its distal-side endto the end tip 25 of the catheter tip 10 so that, on actuation of thesecond operating means 81 via the force transmission means 41 in theform of the second catheter tube 42, a tensile or compressive force canbe transmitted to the second sleeve-shaped member 21 of the catheter tip10.

The exemplary embodiment of the catheter tip 10 further comprises astent holder 15 at the proximal end section of the catheter tip 10. Thestent holder 15 has a passageway extending there through. The distal endsection of the second force transmitting means 41 (second catheter tube42) passes through the passageway of the stent holder 15 and terminatesat the second sleeve-shaped member 21.

The respective sleeve-shaped members 11, 21 of the catheter tip 10 canbe manipulated by corresponding operating means 71, 81 of a handle 70(not shown in FIG. 9). In detail, the first sleeve-shaped member 11 ofthe catheter tip 10 is connected with a first operating means 71 of ahandle 70 by using a first force transmitting means 31. On the otherhand, the second sleeve-shaped member 21 of the catheter tip 10 isconnected to a second operating means 81 of the handle 70 by using asecond force transmitting means 41. In a preferred embodiment of thecatheter shaft 30, the first force transmitting means 31 is constitutedby a first catheter tube 32 defining a first lumen, wherein the secondforce transmitting means 41 is constituted by a second catheter tube 42defining a second lumen. The second catheter tube 42 has a cross-sectionless than the cross-section of the first catheter tube 32, wherein thefirst catheter tube 32 is disposed concentrically and coaxially with thesecond catheter tube 42.

As shown in FIG. 9, the distal end section of the second catheter tube42 passes through the opened front face of the second sleeve-shapedmember 21 and terminates in a cone-shaped end tip 25 of the cathetersystem 1, wherein the base of this cone-shaped end tip 25 defines thedistal front face of the second sleeve-shaped member 21.

The end tip 25 of the catheter system 1 is preferably a soft catheterend tip, for example a soft polymeric catheter end tip.

At its distal end, the first catheter tube 32 terminates after anintermediate flared section in a section with wider cross-sectiondefining the first sleeve-shaped member 11 of the catheter tip 10. Ascan be seen from FIG. 9, the flared section is formed integrally withthe distal end section of the first catheter tube 32. The flared sectionhas a length greater than the length of a collapsed stent to beaccommodated in the catheter tip 10, wherein the difference in thelength between the flared section and the stent in its collapsed staterepresents the length of the stent holder 15.

The catheter shaft 30, which is connected to the catheter tip 10depicted in FIG. 9, also comprises a guiding tube 52 of the kind aspreviously described with reference to the exemplary embodiment depictedin FIG. 1.

The distal end of the guiding tube 52 terminates proximal to thecatheter tip 10. The guiding tube 52 defines a passageway within whichthe first and second catheter tube 42 32, 42 are received such as to bemovable relative to the guiding tube 52.

The distal end of the guiding tube 52 may be tapered such that it abutsthe first catheter tube 32 in one of its possible positions on thecatheter shaft 30.

Reference is made to FIG. 10a , which is a cross-sectional view of acatheter shaft 30 according to an exemplary embodiment.

As can be seen from the illustration in FIG. 10a , the second forcetransmission means 41 in the form of the second catheter tube 42 runsalong the neutral fibre of the catheter shaft 30 inside the firstcatheter tube 32. The space between the first catheter tube 32 and thesecond catheter tube 42 may be filled with a filler material, so that afiller body 40 is formed. The filler material is preferably a relativelyelastic plastic material to allow the catheter shaft 30 to bend overall.The filler body 40 is used for connecting the stent holder 15 of thecatheter tip 10 to the body 70′ of the handle 70.

Alternatively, a stent holder tube 62 may be used for connecting thestent holder 15 of the catheter tip 10 to the body 70′ of the handle 70.The stent holder tube 62 may have a distal end connected to the stentholder 15, a proximal end connected to the body 70′ of the handle 70 anda passageway extending through the stent holder tube 62. Preferably, thestent holder tube 62 has a cross-section less than the cross-section ofthe first catheter tube 32 and greater than the cross-section of thesecond catheter tube 42, wherein the first catheter tube 32 is disposedconcentrically and coaxially with the stent holder tube 62 therebyaccommodating the stent holder tube 62 such that the first catheter tube32 is moveable relative to the stent holder tube 62. The passageway ofthe stent holder tube 62 shall have a diameter sufficient to accommodatethe second catheter tube 42 such that the second catheter tube 42 ismoveable relative to the stent holder tube 62.

As depicted in FIG. 1, the filler body 40 (or the stent holder tube 62)may be connected by means of a fixing 87 to the body 70′ of the handle70. The proximal-side end region of the stent holder 15 attaches at thedistal-side end region of the filler body 40 (see FIG. 8). Theconnection between the stent holder 15 and the filler body 40 ispreferably chosen so that it allows rotation of the stent holder 15relative to the filler body 40. This is especially necessary for controlof the rotation of the positioning hoops of the already partiallyreleased stent during the implantation procedure (see FIG. 12a ).

As an alternative, the complete catheter system 1 can be rotated forappropriate positioning of a stent connected with the catheter tip 10and, in particular the positioning hoops of an already partiallyreleased stent during the implantation procedure. This is possible dueto an appropriate transmission of torque and the flexibility of thecatheter system 1.

In case, a stent holder tube 62 is used for connecting the stent holder15 of the catheter tip 10 to the body 70′ of the handle 70, the stentholder tube 62 may be rotatable relatively to the first and secondcatheter tubes 32, 42 about the longitudinal axis L of the cathetersystem 1. This will be described later in more detail with reference tothe exemplary embodiment depicted in FIG. 10 b.

On the other hand, the second force transmission means 41 in the form ofthe 30 second catheter tube 42 can be turned about the longitudinaldirection L, for example, by means of a rotatable cap 98 which may beprovided at the proximal end region of the handle 70. This rotarymovement is transferred from the second catheter tube 42 direct to theend tip 25 of the catheter tip 10 and thus to the second sleeve-shapedmember 21 of the catheter tip 10.

It is particularly preferred that the second catheter tube 42 runsthrough the body of the stent holder 15 and cooperates with the stentholder 15 with the aid of a suitable toothing, to transmit a turningmoment exerted by means of the rotary cap of the handle 70 on the secondcatheter tube 42 to the stent holder 15, while tensile or compressionforces acting in the longitudinal direction L of the catheter tip 10 arenot transmitted from the second catheter tube 42 to the stent holder 15.

As can also be seen in the illustration in FIG. 10a , a least one fluidchannel 43 may be provided in the filler body 40 of the catheter shaft30, connected at its proximal-side end to an injection adapter 99 b (seeFIG. 2) and at its distal-side end correspondingly to the catheter tip10, consequently ensuring supply of fluid to the catheter tip 10 anddraining of fluid from the catheter tip 10.

Furthermore, a channel may be provided in the filler body 40 foraccommodating a control wire (control wire 35—see FIG. 8), with anoperating means may cooperate with a flexural link region, in case thecatheter shaft 30 is provided with such a flexural link region (see FIG.3 and FIG. 2). In the illustration in FIG. 8, the distal-side end of acontrol wire 35 is fixed to the proximal-side end region of the stentholder 15.

Reference is made to FIG. 10b , which is a cross-sectional view of acatheter shaft 30 according to an alternative exemplary embodiment.

According to the embodiment depicted in FIG. 10b , the first forcetransmitting means 31 may be constituted by a first catheter tube 32defining a first lumen and the second force transmitting means 41 isconstituted by a second catheter tube 42 defining a second lumen. Thesecond catheter tube 42 may have a cross-section less than thecross-section of the first catheter tube 32. The first catheter tube 32may be disposed concentrically and coaxially with the second cathetertube 42 and the second catheter tube 42 is received within the firstlumen defined by the first catheter tube 32.

A stent holder tube 62 is provided for connecting the stent holder 15 tothe handle 70, said stent holder tube 62 having a distal end connectedto the stent holder 15 and a proximal end connected to a body 70′ of thehandle 70.

As can be seen from FIG. 10b , the stent holder tube 62 may have across-section less than the cross-section of the first catheter tube 32.In particular, the first 35 catheter tube 32 may be disposedconcentrically and coaxially with both, the second catheter tube 42 onthe one hand and the stent holder tube 62 on the other hand. Preferably,the stent holder tube 62 has a cross-section less than the cross-sectionof the first catheter tube 32 and greater than the cross-section of thesecond catheter tube 42 such that the stent holder tube 62 is receivedwithin the first lumen defined by the first catheter tube 32 and thesecond catheter tube 42 is received within a passageway defined by thestent holder tube 62. The passageway defined by the stent holder tube 62has a diameter sufficient to accommodate the second catheter tube 42such that the second catheter tube 42 is moveable relative to the stentholder tube 62.

The second lumen defined by the second catheter tube 42 has a diametersufficient to accommodate a guide wire 180. The second catheter tube 42may be made from a rigid material including, for example, nitinol,stainless steel or a rigid plastic material. The material of the distalend section of the second catheter tube 42 may have an increasedflexibility compared to the material of the proximal end section inorder to allow the distal end section of the catheter shaft 30 to passthe aortic arch during insertion of the catheter tip 10. For example,the guiding tube 52 may be a 17F-catheter tube and the first cathetertube 32 may be a 12F-catheter tube.

According to the exemplary embodiment depicted in FIG. 10b , the stentholder tube 62 is made of a rigid material, for example, a rigid plasticmaterial, stainless steel or nitinol. The distal end of the stent holdertube 62 terminates in the stent holder 15 which is also made of a rigidmaterial, for example, a rigid plastic material or stainless steel. Thepassageway defined by the stent holder tube 62 is aligned with a channelwhich passes through the stent holder 15. In this way, the secondcatheter tube 42 is accommodated in the passageway of the stent holdertube 62 and the channel of the stent holder 15 such as to be moveablerelative to the stent holder tube 62 and the stent holder 15.

The embodiments of the insertion system 100 designed fortransarterial/transfemoral access may have a first injection adapter 99a at the proximal end of the handle 70. This first injection adapter 99a is used for flushing the insertion system 100 and as outlet of a guidewire 180, with the aid of which the actual introduction of the cathetershaft 30 with the catheter tip 10 provided at the distal end of thecatheter shaft 30 into the body of the patient is simplified. Thecatheter shaft 30, the catheter tip 10 and the handle 70 are therebythreaded into the guide wire 180 and pushed along it, for example intothe aorta and to the heart of the patient.

In the embodiments of the insertion system 100 designed fortransarterial/transfemoral access, a second injection adapter 99 b mayfurther be provided, by means of which a liquid coolant etc. can bepassed, for example, via the fluid channels 43 (see FIG. 10a ) formed inthe interior of the catheter shaft 30 to the catheter tip 10. With theaid of such a liquid coolant, a stent accommodated in the catheter tip10 can be appropriately cooled while the catheter tip 10 is beingadvanced to the implantation location, as long as the insertion system100 is in its first functional state, in which the catheter tip 10 iscompletely enclosed by the telescopically arranged sleeve-shaped members11 and 21.

The provision of cooling that can be produced with the second injectionadapter 99 b for the stent accommodated in the catheter tip 10 is aparticular advantage when a shape memory material is used as stentmaterial and when the stent can deform under the effect of an externalstimulus from a temporary form to a permanent form, whereby thetemporary form exists in the first configuration of the stent (in thefolded-up state, when the stent is accommodated in the catheter tip 10)and the permanent form exists in the second configuration of the stent(In the expanded state of the stent after release of the stent from thecatheter tip 10).

In the embodiments of the insertion system 100 previously described, theguiding tube 52 is preferably made from a material allowing the guidingtube 52 to be capable of traversing a tortuous pathway in the body ofthe patient without kinking. For example, the guiding tube 52 mayinclude an inner lubricious liner, an outer polymeric jacket, and a coilreinforcement between the inner and outer layers. In addition, it ispreferred when at least on radiopaque band or member is incorporatedwithin the guiding tube's material to allow precise location of thedistal end of the guiding tube 52 for positioning accuracy.

On the other hand, the first and second catheter tubes 32, 42 of thecatheter shaft 30 are preferably made from flexible, sterilizablematerials. These materials may include, for example, polyurethane,silicone, polyvinyl chloride (PVC) nylon and/or polyether block amide,e.g. Pebax®. Furthermore, the first catheter tube 32 and/or secondcatheter tube 42 are/is at least partly made from a less rigid materialthan the guiding tube 52. In an exemplary embodiment, the first cathetertube 32 and/or the second catheter tube 42 are/is at least partly madeof a braided wire construction. In addition, the stent holder tube 62may also be at least partly made of a braided wire construction.

Individual features of different embodiments of this disclosure may becombined in any suitable manner.

A preferred embodiment of a medical device for treatment of a heartvalve stenosis and/or heart valve insufficiency in a patient isdescribed in the following with reference to FIGS. 12a to 12c . Asdepicted, the medical device exhibits an insertion system 100 designedfor transarterial/transfemoral access, as has been described in detailpreviously, for example, with reference to FIGS. 1 to 10.

In addition to the insertion system 100, the medical device has anexpandable heart valve stent 150 mounted in the catheter tip 10 of theinsertion system 100, to which a heart valve prosthesis 160 to beimplanted is fastened. In the first functional state, not shown, thestent 150 exhibits a first, previously definable configuration, in whichit is in its folded-together state. On the other hand, the stent 150 isdesigned to adopt a second previously definable configuration in theimplanted state, in which it exists in its expanded state.

Through the use of the insertion system 100 described above, during theimplantation procedure, the stent 150 is transferred sequentially,following a previously definable sequence of events in steps from itsfirst previously defined configuration into its second previouslydefined configuration.

In detail, the stent 150 that is used with the medical device inaccordance with the depiction in FIGS. 12a to 12c exhibits a firstretaining region, to which the heart valve prosthesis 160 is attached.Further, the stent 150 comprises a second retaining region with threeretaining elements 151, each in the configuration of retaining rings,which can be brought in to a releasable engagement with the retainingelements 16 of the stent holder 15 provided in the catheter tip 10.

In addition, the stent 150 has three retaining hoops 153 to accommodatethe heart valve prosthesis 160 and three positioning hoops 154 forautomatic positioning of the stent 150 at the implantation site, wherebythe respective positioning hoops 154 of the stent 150 are designed infunctional and structural respects to engage the pockets 170 of thenative heart valve during the implantation procedure and in theimplanted state of the stent 150, in particular from the secondfunctional state of the insertion system 100. In detail, eachpositioning hoop 154 and its associated retaining hoop 153 has anessentially U or V-shaped structure, which is closed towards the distalend of the stent 150.

The stent 150, which together with the insertion system 100 forms thebasis of the medical device, is especially suitable for insertion intothe body of a patient with the aid of the insertion system 100 withminimal invasiveness. The distinctive feature of the stent 150 is thatthe three positioning hoops 154 of the stent 150 undertake the functionof automatic positioning of the stent 150 with the heart valveprosthesis 160 attached to it in the aorta of the patient. Thepositioning hoops 154 have radiused head sections, which engage in thepockets 170 of the insufficient heart valve to be replaced by the heartvalve prosthesis during positioning of the stent 150 at the implantationsite. The provision of a total of three positioning hoops 154 takes careof the necessary positioning accuracy in the rotary direction.

In this state shown in 12 a, the catheter tip 10 and the catheter shaft30 of the transarterial or transfemoral insertion system 100 has beeninserted by a puncture of the groin artery of the patient and thecatheter tip 10 has been advanced to the implantation site with the aidof a guide wire 180. In detail, the insertion system 100 to be used isshown already in its second functional state in FIG. 12a . The secondfunctional state of the insertion system 100 designed for transarterialor transfemoral access has been described previously, for example withreference to FIG. 7 b.

In the second functional state, the first sleeve-shaped member 11 of thecatheter tip 10 has already moved by a first predetermined amount ofmovement in a proximal direction, and thus towards the handle 70,leading to a release of the positioning hoops 154 of the stent 150.These already expanded positioning hoops 154 of the stent 150 shown inFIG. 12a are positioned—where necessary by a suitable rotation of thestent holder 15 of the catheter tip 10—in the pockets 170 of the nativeheart valve position. After positioning of the positioning hoops 154 inthe pockets 170 of the native heart valve is complete, the insertionsystem 100 is transferred from its second functional state (see FIG. 7b) into its third functional state (see FIG. 7c ).

The manner in which the insertion system 100 is transferred into itsthird functional state has been described previously, for example withreference to FIG. 7c . FIG. 12b shows the insertion system 100 inaccordance with FIG. 12a , in which the second sleeve-shaped member 21has been displaced in a distal direction so that the first retainingregion of the stent 150 with the retaining hoops 153 and the heart valveprosthesis 160 attached to them are released. These components areopened as a result of the radial forces attacking them, whereby the oldheart valves are clamped between the positioning hoops 154 and theretaining hoops 153.

After the functioning of the heart valve prosthesis 160 has beenchecked, the insertion system 100 is then transferred from its thirdfunctional state into its fourth functional state, as has previouslybeen described, for example with reference to FIG. 7d . FIG. 12 showsthe effect of the transfer of the insertion system 100 into its fourthfunctional state on the heart valve prosthesis 160 and the stent 150.

In detail, it can be seen that, in the fourth functional state of theinsertion system 100, the first sleeve-shaped member 11 of the cathetertip 10 has been displaced further in a proximal direction, as a resultof which the anchorage of the retaining elements 151 on the secondretaining region of the stent 150 is released. This has the result thatthat the second retaining region of the stent 150 can also expand andpress against the vessel wall.

Finally, the catheter tip 10 and the catheter shaft 30 of the insertionsystem 100 are removed again from the body of the patient.

When the heart valve stent 150 is implanted, the old (insufficient)heart valve is pressed against the vessel wall at the same time due tothe self-expanding characteristic of the stent 150, as can be seen inparticular in FIG. 12c . In particular, the semilunar heart valves ofthe insufficient, native heart valve are clamped between the positioninghoops 154 and the retaining hoops 153 because of the expansion of thestent 150, in addition to which the heart valve prosthesis 160 locatedon the first retaining region of the stent 150 is optimally positionedand is stably anchored.

The disclosed solutions provide an improved insertion system 100 withthe stent mountable in the catheter tip 10 of the insertion system 100.The stent may be inserted transarterially by the special insertionsystem 100 and can be optimally positioned, so that a heart valveprosthesis sewn on the first retaining region of the stent can undertakethe function of the insufficient or stenosed native heart valve. Theradial forces developed due to the self-expanding characteristic of thestent ensure a secure anchoring in the area of the aorta. The cathetersystem 1 of the insertion system 100 is preferably an 18 to 21Fintroducer, which is compatible with 21F-insertion tubes and a 0.035″guide wire 180. The length of the catheter system 1 for transarterialaccess should be at least 100 cm. The optionally provided flexural linkregion at the distal region of the catheter system 1 is preferablyapproximately 30 cm.

A further embodiment of a catheter tip 10 for an insertion system fortransfemoral/transarterial insertion of an expandable heart valve stentis shown in its four different functional states in FIGS. 13a to 13d .In detail, the catheter tip 10 is shown in its first functional state inFIG. 13a , in which the catheter shaft with the catheter tip 10 and,where required, with the stent accommodated in it can be inserted intothe patient transarterially or transfemorally and advanced via the aortato the implantation site.

In the first functional state of the catheter tip 10 in accordance withFIG. 13a , the catheter tip 10 is completely closed, whereby the twosleeve-shaped members 11, 21 of the catheter tip 10 abut. In thisembodiment, the two sleeve-shaped members 11, 21 of the catheter tip 10have an equal outer cross-section diameter, thereby not forming a stepin the state depicted in FIG. 13a . The respective inner diameters ofthe sleeve-shaped members 11, 21 are chosen so that the folded-upretaining hoops of a stent, with the heart valve prosthesis fastened tothem where required, can be housed in the second sleeve-shaped member21. The folded-up positioning hoops of the stent housed between thesecond sleeve-shaped member 21 and the first sleeve-shaped member 11 areheld together in their folded form.

In the first functional state of the catheter tip 10, as shown in FIG.13a , the second retaining region of the stent is fixed with the stentholder 15 at the proximal end of the catheter tip 10. For this purpose,the retaining elements (retaining rings etc.) provided at the secondretaining region of the stent are engaged with retaining elements 16 ofthe stent holder 15.

The retaining elements 16 of the stent holder 15 are covered by thefirst sleeve-shaped member 11 of the catheter tip 10 in the firstfunctional state shown in FIG. 13a , so that an engagement betweenretaining elements provided on the second retaining region of a stentand retaining elements 16 of the stent holder 15 would be possible.

The first functional state of the catheter tip 10 shown in FIG. 13a ismaintained during the transarterial insertion procedure. On reaching theimplantation location, the catheter tip 10 is transferred from the firstfunctional state shown in FIG. 13a to the second functional state shownin FIG. 13b , by transferring the first operating means of the handle(first operating means 71 shown in the embodiment of the wheel in FIG.7) from the first position into the second position. The longitudinaldisplacement stroke transferred by actuation of the first operatingmeans 71 to the first sleeve-shaped member 11 of the catheter tip 10effects a displacement of the first sleeve-shaped member 11 relative tothe stent holder 15 in the proximal direction, thus towards the handle70.

The longitudinal displacement stroke executed on the first sleeve-shapedmember 11 of the catheter tip 10 during the transition from the firstfunctional state (see FIG. 13a ) to the second functional state (seeFIG. 13b ) by the first operating means 71 of the handle 70 via acorresponding first force transmission means 31 is previously defined sothat the first sleeve-shaped member 11 is displaced relative to thestent holder 15 in the proximal direction just so far that thepositioning hoops of a stent housed in the catheter tip 10 would bereleased, though the distal end of the first sleeve-shaped member 11 ofthe catheter tip 10 would still cover the retaining elements 16 of thestent holder 15, so that the engagement between the retaining elementsprovided at the second retaining region of the stent and the retainingelements 16 of the stent holder 15 would be secure.

Since the second sleeve-shaped member 21 is not manipulated during thetransition from the first functional state into the second functionalstate, the first retaining region of a stent housed in the catheter tip10 with the heart valve prosthesis fastened to it would continue to behoused in its folded together state in the sleeve-shaped element of thesecond sleeve-shaped member 21.

The positioning hoops of a stent housed in the catheter tip 10 releasedin the 20 second functional state of the catheter tip 10 are opened as aresult of the radial forces acting on them and can thus be positioned inthe pockets of the insufficient native heart valve. Followingappropriate positioning of the positioning hoops of the stent in thepockets of the native heart valve, the catheter tip 10 is transferredfrom the second functional state shown in FIG. 13b into the thirdfunctional state shown in FIG. 13c . This is done my manipulation of thesecond operating means 81 of the handle, after the securing element 89associated with the second operating means 81 has been removed.

On actuation of the second operating means 81 of the handle, the secondsleeve-shaped member 21 of the catheter tip 10 associated with thesecond operating means 81 is moved relative to the stent holder 15 by apreviously established longitudinal displacement stroke defined with thesecond operating means 81 in a distal direction, thus away from thehandle 70. The longitudinal displacement stroke acting on the secondsleeve-shaped member 21 is chosen so that the sleeve-shaped member 21 nolonger covers the first retaining region of a stent housed in thecatheter tip 10 with the heart valve prosthesis fastened to it, whererequired, and thus releases the first retaining region of the stent. Dueto the action of the radial forces, the distal retaining region of thestent with the heart valve prosthesis attached to it, where required,unfolds completely.

Since the first operating means 71 of the handle 70 and the associatedfirst sleeve-shaped member 11 of the catheter tip 10 are not manipulatedduring the transition from the second functional state in accordancewith FIG. 13b into the third functional state in accordance with FIG.13c , the distal end region of the first sleeve-shaped member 11continues to cover the retaining elements 16 of the stent holder 15, sothat the engagement between the retaining elements of a stent housed inthe catheter tip 10 and the retaining elements 16 of the stent holder 15is secure and the proximal retaining region of the stent is in itsfolded-up state. This anchorage of the stent to the catheter tip 10 ofthe insertion system 100 allows an explantation of a stent that isalready partially unfolded by returning the catheter tip 10 from thethird functional state, by appropriate manipulation of the secondoperating means 81 of the handle 70, to the second functional state andthen by suitable actuation of the first operating means 71 transfer tothe first functional state.

If an explantation of the stent with the heart valve prosthesis attachedto it, where required, is unnecessary, the catheter tip 10 istransferred from the third functional state shown in FIG. 13c into thefourth functional state shown in FIG. 13d , by turning the firstoperating means 71 of the handle 70 further from the second position tothe third position after removal of the securing element 79 (lockingelement). This manipulation of the first operating means 71 that can beeffected after removal of the securing element 79 results in a furtherdefined movement of the first sleeve-shaped member 11 relative to thestent holder 15 of the catheter tip 10 in a proximal direction, thustowards the handle 70. The longitudinal displacement stroke executed onthe first sleeve-shaped member 11 is chosen so that the distal end ofthe first sleeve-shaped member 11 no longer covers the retainingelements 16 of the stent holder 15, as a result of which an engagementbetween the retaining elements of a stent housed in the catheter tip 10and the retaining elements 16 of the stent holder 15 can be released,which would also lead to a complete release of the second retainingregion of the stent and a complete separation of the stent from thecatheter tip 10 and correspondingly to a complete unfolding of thestent.

In the embodiment of the catheter tip 10 depicted in FIGS. 13a-e , astent holder tube 62 is used for connecting the stent holder 15 of thecatheter tip 10 to the body 70′ of the handle 70. The stent holder tube62 has a distal end connected to the stent holder 15, a proximal endconnected to the body 70′ of the handle 70 and a passageway extendingthrough the stent holder tube 62. In addition, an extension portion 62′of the stent holder tube 62 is provided, said extension portionextending from the distal end of the stent holder 15 to a supportsection 63. The support section 63 may be a tapered portion which iscompletely accommodated in the second sleeve-shaped member 21 when thecatheter tip 10 is in its first and second functional state (cf. FIGS.13a, b ).

Preferably, the stent holder tube 62 and its extension 62′ have across-section less than the cross-section of the first catheter tube 32and greater than the cross-section of the second catheter tube 42 (notshown in FIGS. 13a-e ), wherein the first catheter tube 32 is disposedconcentrically and coaxially with the stent holder tube 62 therebyaccommodating the stent holder tube 62 such that the first catheter tube32 is moveable relative to the stent holder tube 62. The passageway ofthe stent holder tube 62 shall have a diameter sufficient to accommodatethe second catheter tube 42 such that the second catheter tube 42 ismoveable relative to the stent holder tube 62.

FIG. 13e shows a side elevation of the embodiment of the catheter tip 10in accordance with FIG. 13a-d , whereby the catheter tip 10 is in itsstate after releasing a stent housed in the catheter tip 10 and ready tobe removed again from the body of the patient. In this state of thecatheter tip 10, the first sleeve-shaped member 11 is pushed bymanipulation of the first operating means 71 of the handle 70 such thatthe first sleeve-shaped member 11 is in its most distal position, inwhich the distal end of the first sleeve-shaped member 11 abuts againstthe proximal end of the second sleeve-shaped member 21 without any gapor step there between. For securing this gap and step free state, thedistal end of the first sleeve-shaped members 11 is supported by thealready mentioned support section 63.

The disclosed solution is not limited to the preferred embodimentdescribed in the attached drawings. On the contrary, combinations of theindividual features described in detail are also possible.

List of reference numerals 1 catheter system 10 catheter tip 11 firstsleeve-shaped member 15 stent holder 16 retaining elements 21 secondsleeve-shaped member 25 catheter end tip 30 catheter shaft 31 firstforce transmission means 32 first catheter tube 34 flexural link region36 channel 35 control wire 40 filler body 41 second force transmissionmeans 42 second catheter tube 43 fluid channels 51 guiding means 52guiding tube 53 inlet port 62 stent holder tube 62′ extension of stentholder tube 63 support means 70 handle 70′ body of the handle 71 firstoperating means 72 first guide 73 first pusher 74 first slide 74′ screwcap 75 first stop 76 second stop 77 additional stop 77′ locking element79 securing element 81 second operating means 82 second guide 83 secondpusher 84 second slide 85 first stop 86 second stop 87 fixing 88 grip 89securing element 96 third operating means 97 compression spring 97afirst stop 97b second stop 98 turning mechanism/rotatable cap 99a firstinjection adapter 99b second injection adapter 100 insertion system 150stent 151 retaining elements 153 retaining hoops 154 positioning hoops160 heart valve prosthesis 170 pockets of native heart valve 180 guidingwire L longitudinal direction of insertion system 100

The invention claimed is:
 1. A delivery system for introducing anexpandable stent into a heart of a patient, the delivery systemcomprising: a stent; and a catheter comprising a distal end portion foraccommodating the stent in a collapsed configuration, the distal endportion comprising: a catheter tube; an end support coupled to a distalend of the catheter tube; a stent holder; a sheath movable relative toeach of the catheter tube and the stent holder, the sheath having afirst outer cross-sectional diameter equal to a second outercross-sectional diameter of the end support; a first compartmentradially between the catheter tube and the first outer cross-sectionaldiameter of the sheath, and adjacent to the end support; and a secondcompartment radially between the catheter tube and the first outercross-sectional diameter of the sheath, the second compartment beingproximal to the first compartment; wherein an outer surface of the stentholder is tapered, and a proximal outer surface of the end support istapered; and wherein the stent is self-expandable and configured to behoused within the distal end of the catheter in a collapsedconfiguration, the stent comprising three arches and three retainingelements, the three retaining elements of the stent being releasablyengaged with the stent holder.
 2. The delivery system of claim 1,wherein the distal end portion includes retaining elements configured toreceive the three retaining elements of the stent.
 3. The deliverysystem of claim 2, wherein the retaining elements of the distal endportion are provided at a proximal end of the stent holder.
 4. Thedelivery system of claim 2, wherein the three retaining elements of thedistal end are equidistant to one another.
 5. The delivery system ofclaim 1, further comprising an end tip that is cone-shaped.
 6. Thedelivery system of claim 1, wherein the catheter tube defines a lumenfor receiving a guidewire.
 7. The delivery system of claim 1, whereinthe catheter comprises a handle coupled to a shaft that includes thedistal end portion, the shaft being flexible to allow the distal endportion to navigate through an aortic arch of the patient.
 8. Thedelivery system of claim 7, wherein the handle includes a rotationalactuator operably connected to the sheath, and wherein rotationalmovement of the rotational actuator corresponds to longitudinal movementof the sheath.
 9. The delivery system of claim 1, wherein the stenthoused within the first compartment of the distal end portion in thecollapsed configuration.
 10. The delivery system of claim 9, wherein anapex of each arch points in a distal direction towards an end tip. 11.The delivery system of claim 9, wherein the three retaining elements ofthe stent are in the form of retaining eyes.
 12. A system forintroducing a stent into a heart of a patient, the system comprising: astent; and a catheter comprising a handle coupled to a shaft, whereinthe shaft includes a distal end comprising: a catheter tube; an endsupport coupled to a distal end of the catheter tube; a stent holder; asheath movable relative to each of the catheter tube and the stentholder, the sheath having a first outer cross-sectional diameter equalto a second outer cross-sectional diameter of the end support; a firstcompartment radially between the catheter tube and the first outercross-sectional diameter of the sheath, and adjacent to the end support;and a second compartment radially between the catheter tube and thefirst outer cross-sectional diameter of the sheath, the secondcompartment being proximal to the first compartment; wherein the stentis self-expandable and configured to be housed within the distal end ina collapsed configuration, the stent comprising three U-shaped archesand three retaining elements housed within the first compartment, thethree retaining elements of the stent being releasably engaged withthree corresponding retaining elements of the distal end; and wherein anouter surface of the stent holder is tapered and a proximal outersurface of the end support is tapered.
 13. The system of claim 12,wherein the shaft is flexible to allow the distal end portion tonavigate through an aortic arch of the patient.
 14. The system of claim12, wherein a proximal portion of the handle includes a rotationalactuator operably connected to the sheath, and wherein rotationalmovement of the rotational actuator corresponds to longitudinal movementof the sheath relative to the catheter tube.
 15. A method forintroducing an expandable stent into a heart of a patient, the methodcomprising: advancing a distal end portion of a catheter through anaortic arch of a patient towards an aortic valve of the patient, thedistal end portion comprising: a catheter tube; an end support coupledto a distal end of the catheter tube and comprising a proximal outersurface that is tapered; a stent holder comprising an outer surface thatis tapered; and a sheath movable relative to each of the catheter tubeand the stent holder, the sheath having a first outer cross-sectionaldiameter equal to a second outer cross-sectional diameter of the endsupport; a first compartment radially between the catheter tube and thefirst outer cross-sectional diameter of the sheath, and adjacent to theend support; and a second compartment radially between the catheter tubeand the first outer cross-sectional diameter of the sheath, the secondcompartment being proximal to the first compartment; introducing thedistal end portion through the aortic valve, such that the end supportis positioned on a first side of the aortic valve, and the firstcompartment and the second compartment are each positioned at leastpartially on a second side of the aortic valve, wherein the firstcompartment contains three U-shaped arches of the stent in a collapsedconfiguration; uncovering the three U-shaped arches such that the threeU-shaped arches self-expand; positioning each U-shaped arch within acorresponding pocket of the aortic valve; and uncovering a remainder ofthe stent while at least a portion of the remainder of the stent isradially inward of native leaflets of the aortic valve and radiallyinward of the three U-shaped arches, such that the remainder of thestent self-expands radially outward towards the three U-shaped arches.16. The method of claim 15, wherein uncovering the three U-shaped archesincludes moving the sheath in a proximal direction by rotating arotational actuator of the handle of the catheter.
 17. The method ofclaim 15, wherein the catheter tube defines a lumen that receives aguidewire, and the method further includes advancing the guidewirethrough the aortic arch before advancing the distal end portion of thecatheter through the aortic arch.
 18. The method of claim 15, whereinthe distal end portion of the catheter includes three retaining elementsthat are engaged with three corresponding retaining elements of thestent before the three U-shaped arches self-expand.
 19. The method ofclaim 15, wherein uncovering the remainder of the stent includes movingthe sheath in a proximal direction.